/**
 * Created by zhangpengcheng on 2019/10/9.
 */

/*!
 * Vue.js v2.6.10
 * (c) 2014-2019 Evan You
 * Released under the MIT License.
 */
(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
        typeof define === 'function' && define.amd ? define(factory) :
            (global = global || self, global.Vue = factory());
}(this, function () { 'use strict';

    /*  */

    var emptyObject = Object.freeze({});

    // These helpers produce better VM code in JS engines due to their
    // explicitness and function inlining.
    function isUndef (v) {
        return v === undefined || v === null
    }

    function isDef (v) {
        return v !== undefined && v !== null
    }

    function isTrue (v) {
        return v === true
    }

    function isFalse (v) {
        return v === false
    }

    /**
     * Check if value is primitive.
     */
    function isPrimitive (value) {
        return (
            typeof value === 'string' ||
            typeof value === 'number' ||
                // $flow-disable-line
            typeof value === 'symbol' ||
            typeof value === 'boolean'
        )
    }

    /**
     * Quick object check - this is primarily used to tell
     * Objects from primitive values when we know the value
     * is a JSON-compliant type.
     */
    function isObject (obj) {
        return obj !== null && typeof obj === 'object'
    }

    /**
     * Get the raw type string of a value, e.g., [object Object].
     */
    var _toString = Object.prototype.toString;

    function toRawType (value) {
        return _toString.call(value).slice(8, -1)
    }

    /**
     * Strict object type check. Only returns true
     * for plain JavaScript objects.
     */
    function isPlainObject (obj) {
        return _toString.call(obj) === '[object Object]'
    }

    function isRegExp (v) {
        return _toString.call(v) === '[object RegExp]'
    }

    /**
     * Check if val is a valid array index.
     */
    function isValidArrayIndex (val) {
        var n = parseFloat(String(val));
        return n >= 0 && Math.floor(n) === n && isFinite(val)
    }

    function isPromise (val) {
        return (
            isDef(val) &&
            typeof val.then === 'function' &&
            typeof val.catch === 'function'
        )
    }

    /**
     * Convert a value to a string that is actually rendered.
     */
    function toString (val) {
        return val == null
            ? ''
            : Array.isArray(val) || (isPlainObject(val) && val.toString === _toString)
            ? JSON.stringify(val, null, 2)
            : String(val)
    }

    /**
     * Convert an input value to a number for persistence.
     * If the conversion fails, return original string.
     */
    function toNumber (val) {
        var n = parseFloat(val);
        return isNaN(n) ? val : n
    }

    /**
     * Make a map and return a function for checking if a key
     * is in that map.
     */
    function makeMap (
        str,
        expectsLowerCase
    ) {
        var map = Object.create(null);
        var list = str.split(',');
        for (var i = 0; i < list.length; i++) {
            map[list[i]] = true;
        }
        return expectsLowerCase
            ? function (val) { return map[val.toLowerCase()]; }
            : function (val) { return map[val]; }
    }

    /**
     * Check if a tag is a built-in tag.
     */
    var isBuiltInTag = makeMap('slot,component', true);

    /**
     * Check if an attribute is a reserved attribute.
     */
    var isReservedAttribute = makeMap('key,ref,slot,slot-scope,is');

    /**
     * Remove an item from an array.
     */
    function remove (arr, item) {
        if (arr.length) {
            var index = arr.indexOf(item);
            if (index > -1) {
                return arr.splice(index, 1)
            }
        }
    }

    /**
     * Check whether an object has the property.
     */
    var hasOwnProperty = Object.prototype.hasOwnProperty;
    function hasOwn (obj, key) {
        return hasOwnProperty.call(obj, key)
    }

    /**
     * Create a cached version of a pure function.
     */
    function cached (fn) {
        var cache = Object.create(null);
        return (function cachedFn (str) {
            var hit = cache[str];
            return hit || (cache[str] = fn(str))
        })
    }

    /**
     * Camelize a hyphen-delimited string.
     */
    var camelizeRE = /-(\w)/g;
    var camelize = cached(function (str) {
        return str.replace(camelizeRE, function (_, c) { return c ? c.toUpperCase() : ''; })
    });

    /**
     * Capitalize a string.
     */
    var capitalize = cached(function (str) {
        return str.charAt(0).toUpperCase() + str.slice(1)
    });

    /**
     * Hyphenate a camelCase string.
     */
    var hyphenateRE = /\B([A-Z])/g;
    var hyphenate = cached(function (str) {
        return str.replace(hyphenateRE, '-$1').toLowerCase()
    });

    /**
     * Simple bind polyfill for environments that do not support it,
     * e.g., PhantomJS 1.x. Technically, we don't need this anymore
     * since native bind is now performant enough in most browsers.
     * But removing it would mean breaking code that was able to run in
     * PhantomJS 1.x, so this must be kept for backward compatibility.
     */

    /* istanbul ignore next */
    function polyfillBind (fn, ctx) {
        function boundFn (a) {
            var l = arguments.length;
            return l
                ? l > 1
                ? fn.apply(ctx, arguments)
                : fn.call(ctx, a)
                : fn.call(ctx)
        }

        boundFn._length = fn.length;
        return boundFn
    }

    function nativeBind (fn, ctx) {
        return fn.bind(ctx)
    }

    var bind = Function.prototype.bind
        ? nativeBind
        : polyfillBind;

    /**
     * Convert an Array-like object to a real Array.
     */
    function toArray (list, start) {
        start = start || 0;
        var i = list.length - start;
        var ret = new Array(i);
        while (i--) {
            ret[i] = list[i + start];
        }
        return ret
    }

    /**
     * Mix properties into target object.
     */
    function extend (to, _from) {
        for (var key in _from) {
            to[key] = _from[key];
        }
        return to
    }

    /**
     * Merge an Array of Objects into a single Object.
     */
    function toObject (arr) {
        var res = {};
        for (var i = 0; i < arr.length; i++) {
            if (arr[i]) {
                extend(res, arr[i]);
            }
        }
        return res
    }

    /* eslint-disable no-unused-vars */

    /**
     * Perform no operation.
     * Stubbing args to make Flow happy without leaving useless transpiled code
     * with ...rest (https://flow.org/blog/2017/05/07/Strict-Function-Call-Arity/).
     */
    function noop (a, b, c) {}

    /**
     * Always return false.
     */
    var no = function (a, b, c) { return false; };

    /* eslint-enable no-unused-vars */

    /**
     * Return the same value.
     */
    var identity = function (_) { return _; };

    /**
     * Generate a string containing static keys from compiler modules.
     */
    function genStaticKeys (modules) {
        return modules.reduce(function (keys, m) {
            return keys.concat(m.staticKeys || [])
        }, []).join(',')
    }

    /**
     * Check if two values are loosely equal - that is,
     * if they are plain objects, do they have the same shape?
     */
    function looseEqual (a, b) {
        if (a === b) { return true }
        var isObjectA = isObject(a);
        var isObjectB = isObject(b);
        if (isObjectA && isObjectB) {
            try {
                var isArrayA = Array.isArray(a);
                var isArrayB = Array.isArray(b);
                if (isArrayA && isArrayB) {
                    return a.length === b.length && a.every(function (e, i) {
                            return looseEqual(e, b[i])
                        })
                } else if (a instanceof Date && b instanceof Date) {
                    return a.getTime() === b.getTime()
                } else if (!isArrayA && !isArrayB) {
                    var keysA = Object.keys(a);
                    var keysB = Object.keys(b);
                    return keysA.length === keysB.length && keysA.every(function (key) {
                            return looseEqual(a[key], b[key])
                        })
                } else {
                    /* istanbul ignore next */
                    return false
                }
            } catch (e) {
                /* istanbul ignore next */
                return false
            }
        } else if (!isObjectA && !isObjectB) {
            return String(a) === String(b)
        } else {
            return false
        }
    }

    /**
     * Return the first index at which a loosely equal value can be
     * found in the array (if value is a plain object, the array must
     * contain an object of the same shape), or -1 if it is not present.
     */
    function looseIndexOf (arr, val) {
        for (var i = 0; i < arr.length; i++) {
            if (looseEqual(arr[i], val)) { return i }
        }
        return -1
    }

    /**
     * Ensure a function is called only once.
     */
    function once (fn) {
        var called = false;
        return function () {
            if (!called) {
                called = true;
                fn.apply(this, arguments);
            }
        }
    }

    var SSR_ATTR = 'data-server-rendered';

    var ASSET_TYPES = [
        'component',
        'directive',
        'filter'
    ];

    var LIFECYCLE_HOOKS = [
        'beforeCreate',
        'created',
        'beforeMount',
        'mounted',
        'beforeUpdate',
        'updated',
        'beforeDestroy',
        'destroyed',
        'activated',
        'deactivated',
        'errorCaptured',
        'serverPrefetch'
    ];

    /*  */



    var config = ({
        /**
         * Option merge strategies (used in core/util/options)
         */
        // $flow-disable-line
        optionMergeStrategies: Object.create(null),

        /**
         * Whether to suppress warnings.
         */
        silent: false,

        /**
         * Show production mode tip message on boot?
         */
        productionTip: "development" !== 'production',

        /**
         * Whether to enable devtools
         */
        devtools: "development" !== 'production',

        /**
         * Whether to record perf
         */
        performance: false,

        /**
         * Error handler for watcher errors
         */
        errorHandler: null,

        /**
         * Warn handler for watcher warns
         */
        warnHandler: null,

        /**
         * Ignore certain custom elements
         */
        ignoredElements: [],

        /**
         * Custom user key aliases for v-on
         */
        // $flow-disable-line
        keyCodes: Object.create(null),

        /**
         * Check if a tag is reserved so that it cannot be registered as a
         * component. This is platform-dependent and may be overwritten.
         */
        isReservedTag: no,

        /**
         * Check if an attribute is reserved so that it cannot be used as a component
         * prop. This is platform-dependent and may be overwritten.
         */
        isReservedAttr: no,

        /**
         * Check if a tag is an unknown element.
         * Platform-dependent.
         */
        isUnknownElement: no,

        /**
         * Get the namespace of an element
         */
        getTagNamespace: noop,

        /**
         * Parse the real tag name for the specific platform.
         */
        parsePlatformTagName: identity,

        /**
         * Check if an attribute must be bound using property, e.g. value
         * Platform-dependent.
         */
        mustUseProp: no,

        /**
         * Perform updates asynchronously. Intended to be used by Vue Test Utils
         * This will significantly reduce performance if set to false.
         */
        async: true,

        /**
         * Exposed for legacy reasons
         */
        _lifecycleHooks: LIFECYCLE_HOOKS
    });

    /*  */

    /**
     * unicode letters used for parsing html tags, component names and property paths.
     * using https://www.w3.org/TR/html53/semantics-scripting.html#potentialcustomelementname
     * skipping \u10000-\uEFFFF due to it freezing up PhantomJS
     */
    var unicodeRegExp = /a-zA-Z\u00B7\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u037D\u037F-\u1FFF\u200C-\u200D\u203F-\u2040\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF\uFDF0-\uFFFD/;

    /**
     * Check if a string starts with $ or _
     */
    function isReserved (str) {
        var c = (str + '').charCodeAt(0);
        return c === 0x24 || c === 0x5F
    }

    /**
     * Define a property.
     */
    function def (obj, key, val, enumerable) {
        Object.defineProperty(obj, key, {
            value: val,
            enumerable: !!enumerable,
            writable: true,
            configurable: true
        });
    }

    /**
     * Parse simple path.
     */
    var bailRE = new RegExp(("[^" + (unicodeRegExp.source) + ".$_\\d]"));
    function parsePath (path) {
        if (bailRE.test(path)) {
            return
        }
        var segments = path.split('.');
        return function (obj) {
            for (var i = 0; i < segments.length; i++) {
                if (!obj) { return }
                obj = obj[segments[i]];
            }
            return obj
        }
    }

    /*  */

    // can we use __proto__?
    var hasProto = '__proto__' in {};

    // Browser environment sniffing
    var inBrowser = typeof window !== 'undefined';
    var inWeex = typeof WXEnvironment !== 'undefined' && !!WXEnvironment.platform;
    var weexPlatform = inWeex && WXEnvironment.platform.toLowerCase();
    var UA = inBrowser && window.navigator.userAgent.toLowerCase();
    var isIE = UA && /msie|trident/.test(UA);
    var isIE9 = UA && UA.indexOf('msie 9.0') > 0;
    var isEdge = UA && UA.indexOf('edge/') > 0;
    var isAndroid = (UA && UA.indexOf('android') > 0) || (weexPlatform === 'android');
    var isIOS = (UA && /iphone|ipad|ipod|ios/.test(UA)) || (weexPlatform === 'ios');
    var isChrome = UA && /chrome\/\d+/.test(UA) && !isEdge;
    var isPhantomJS = UA && /phantomjs/.test(UA);
    var isFF = UA && UA.match(/firefox\/(\d+)/);

    // Firefox has a "watch" function on Object.prototype...
    var nativeWatch = ({}).watch;

    var supportsPassive = false;
    if (inBrowser) {
        try {
            var opts = {};
            Object.defineProperty(opts, 'passive', ({
                get: function get () {
                    /* istanbul ignore next */
                    supportsPassive = true;
                }
            })); // https://github.com/facebook/flow/issues/285
            window.addEventListener('test-passive', null, opts);
        } catch (e) {}
    }

    // this needs to be lazy-evaled because vue may be required before
    // vue-server-renderer can set VUE_ENV
    var _isServer;
    var isServerRendering = function () {
        if (_isServer === undefined) {
            /* istanbul ignore if */
            if (!inBrowser && !inWeex && typeof global !== 'undefined') {
                // detect presence of vue-server-renderer and avoid
                // Webpack shimming the process
                _isServer = global['process'] && global['process'].env.VUE_ENV === 'server';
            } else {
                _isServer = false;
            }
        }
        return _isServer
    };

    // detect devtools
    var devtools = inBrowser && window.__VUE_DEVTOOLS_GLOBAL_HOOK__;

    /* istanbul ignore next */
    function isNative (Ctor) {
        return typeof Ctor === 'function' && /native code/.test(Ctor.toString())
    }

    var hasSymbol =
        typeof Symbol !== 'undefined' && isNative(Symbol) &&
        typeof Reflect !== 'undefined' && isNative(Reflect.ownKeys);

    var _Set;
    /* istanbul ignore if */ // $flow-disable-line
    if (typeof Set !== 'undefined' && isNative(Set)) {
        // use native Set when available.
        _Set = Set;
    } else {
        // a non-standard Set polyfill that only works with primitive keys.
        _Set = /*@__PURE__*/(function () {
            function Set () {
                this.set = Object.create(null);
            }
            Set.prototype.has = function has (key) {
                return this.set[key] === true
            };
            Set.prototype.add = function add (key) {
                this.set[key] = true;
            };
            Set.prototype.clear = function clear () {
                this.set = Object.create(null);
            };

            return Set;
        }());
    }

    /*  */

    var warn = noop;
    var tip = noop;
    var generateComponentTrace = (noop); // work around flow check
    var formatComponentName = (noop);

    {
        var hasConsole = typeof console !== 'undefined';
        var classifyRE = /(?:^|[-_])(\w)/g;
        var classify = function (str) { return str
            .replace(classifyRE, function (c) { return c.toUpperCase(); })
            .replace(/[-_]/g, ''); };

        warn = function (msg, vm) {
            var trace = vm ? generateComponentTrace(vm) : '';

            if (config.warnHandler) {
                config.warnHandler.call(null, msg, vm, trace);
            } else if (hasConsole && (!config.silent)) {
                console.error(("[Vue warn]: " + msg + trace));
            }
        };

        tip = function (msg, vm) {
            if (hasConsole && (!config.silent)) {
                console.warn("[Vue tip]: " + msg + (
                        vm ? generateComponentTrace(vm) : ''
                    ));
            }
        };

        formatComponentName = function (vm, includeFile) {
            if (vm.$root === vm) {
                return '<Root>'
            }
            var options = typeof vm === 'function' && vm.cid != null
                ? vm.options
                : vm._isVue
                ? vm.$options || vm.constructor.options
                : vm;
            var name = options.name || options._componentTag;
            var file = options.__file;
            if (!name && file) {
                var match = file.match(/([^/\\]+)\.vue$/);
                name = match && match[1];
            }

            return (
                (name ? ("<" + (classify(name)) + ">") : "<Anonymous>") +
                (file && includeFile !== false ? (" at " + file) : '')
            )
        };

        var repeat = function (str, n) {
            var res = '';
            while (n) {
                if (n % 2 === 1) { res += str; }
                if (n > 1) { str += str; }
                n >>= 1;
            }
            return res
        };

        generateComponentTrace = function (vm) {
            if (vm._isVue && vm.$parent) {
                var tree = [];
                var currentRecursiveSequence = 0;
                while (vm) {
                    if (tree.length > 0) {
                        var last = tree[tree.length - 1];
                        if (last.constructor === vm.constructor) {
                            currentRecursiveSequence++;
                            vm = vm.$parent;
                            continue
                        } else if (currentRecursiveSequence > 0) {
                            tree[tree.length - 1] = [last, currentRecursiveSequence];
                            currentRecursiveSequence = 0;
                        }
                    }
                    tree.push(vm);
                    vm = vm.$parent;
                }
                return '\n\nfound in\n\n' + tree
                        .map(function (vm, i) { return ("" + (i === 0 ? '---> ' : repeat(' ', 5 + i * 2)) + (Array.isArray(vm)
                            ? ((formatComponentName(vm[0])) + "... (" + (vm[1]) + " recursive calls)")
                            : formatComponentName(vm))); })
                        .join('\n')
            } else {
                return ("\n\n(found in " + (formatComponentName(vm)) + ")")
            }
        };
    }

    /*  */

    var uid = 0;

    /**
     * A dep is an observable that can have multiple
     * directives subscribing to it.
     */
    var Dep = function Dep () {
        this.id = uid++;
        this.subs = [];
    };

    Dep.prototype.addSub = function addSub (sub) {
        this.subs.push(sub);
    };

    Dep.prototype.removeSub = function removeSub (sub) {
        remove(this.subs, sub);
    };

    Dep.prototype.depend = function depend () {
        if (Dep.target) {
            Dep.target.addDep(this);
        }
    };

    Dep.prototype.notify = function notify () {
        // stabilize the subscriber list first
        var subs = this.subs.slice();
        if (!config.async) {
            // subs aren't sorted in scheduler if not running async
            // we need to sort them now to make sure they fire in correct
            // order
            subs.sort(function (a, b) { return a.id - b.id; });
        }
        for (var i = 0, l = subs.length; i < l; i++) {
            subs[i].update();
        }
    };

    // The current target watcher being evaluated.
    // This is globally unique because only one watcher
    // can be evaluated at a time.
    Dep.target = null;
    var targetStack = [];

    function pushTarget (target) {
        targetStack.push(target);
        Dep.target = target;
    }

    function popTarget () {
        targetStack.pop();
        Dep.target = targetStack[targetStack.length - 1];
    }

    /*  */

    var VNode = function VNode (
        tag,
        data,
        children,
        text,
        elm,
        context,
        componentOptions,
        asyncFactory
    ) {
        this.tag = tag;
        this.data = data;
        this.children = children;
        this.text = text;
        this.elm = elm;
        this.ns = undefined;
        this.context = context;
        this.fnContext = undefined;
        this.fnOptions = undefined;
        this.fnScopeId = undefined;
        this.key = data && data.key;
        this.componentOptions = componentOptions;
        this.componentInstance = undefined;
        this.parent = undefined;
        this.raw = false;
        this.isStatic = false;
        this.isRootInsert = true;
        this.isComment = false;
        this.isCloned = false;
        this.isOnce = false;
        this.asyncFactory = asyncFactory;
        this.asyncMeta = undefined;
        this.isAsyncPlaceholder = false;
    };

    var prototypeAccessors = { child: { configurable: true } };

    // DEPRECATED: alias for componentInstance for backwards compat.
    /* istanbul ignore next */
    prototypeAccessors.child.get = function () {
        return this.componentInstance
    };

    Object.defineProperties( VNode.prototype, prototypeAccessors );

    var createEmptyVNode = function (text) {
        if ( text === void 0 ) text = '';

        var node = new VNode();
        node.text = text;
        node.isComment = true;
        return node
    };

    function createTextVNode (val) {
        return new VNode(undefined, undefined, undefined, String(val))
    }

    // optimized shallow clone
    // used for static nodes and slot nodes because they may be reused across
    // multiple renders, cloning them avoids errors when DOM manipulations rely
    // on their elm reference.
    function cloneVNode (vnode) {
        var cloned = new VNode(
            vnode.tag,
            vnode.data,
            // #7975
            // clone children array to avoid mutating original in case of cloning
            // a child.
            vnode.children && vnode.children.slice(),
            vnode.text,
            vnode.elm,
            vnode.context,
            vnode.componentOptions,
            vnode.asyncFactory
        );
        cloned.ns = vnode.ns;
        cloned.isStatic = vnode.isStatic;
        cloned.key = vnode.key;
        cloned.isComment = vnode.isComment;
        cloned.fnContext = vnode.fnContext;
        cloned.fnOptions = vnode.fnOptions;
        cloned.fnScopeId = vnode.fnScopeId;
        cloned.asyncMeta = vnode.asyncMeta;
        cloned.isCloned = true;
        return cloned
    }

    /*
     * not type checking this file because flow doesn't play well with
     * dynamically accessing methods on Array prototype
     */

    var arrayProto = Array.prototype;
    var arrayMethods = Object.create(arrayProto);

    var methodsToPatch = [
        'push',
        'pop',
        'shift',
        'unshift',
        'splice',
        'sort',
        'reverse'
    ];

    /**
     * Intercept mutating methods and emit events
     */
    methodsToPatch.forEach(function (method) {
        // cache original method
        var original = arrayProto[method];
        def(arrayMethods, method, function mutator () {
            var args = [], len = arguments.length;
            while ( len-- ) args[ len ] = arguments[ len ];

            var result = original.apply(this, args);
            var ob = this.__ob__;
            var inserted;
            switch (method) {
                case 'push':
                case 'unshift':
                    inserted = args;
                    break
                case 'splice':
                    inserted = args.slice(2);
                    break
            }
            if (inserted) { ob.observeArray(inserted); }
            // notify change
            ob.dep.notify();
            return result
        });
    });

    /*  */

    var arrayKeys = Object.getOwnPropertyNames(arrayMethods);

    /**
     * In some cases we may want to disable observation inside a component's
     * update computation.
     */
    var shouldObserve = true;

    function toggleObserving (value) {
        shouldObserve = value;
    }

    /**
     * Observer class that is attached to each observed
     * object. Once attached, the observer converts the target
     * object's property keys into getter/setters that
     * collect dependencies and dispatch updates.
     */
    var Observer = function Observer (value) {
        this.value = value;
        this.dep = new Dep();
        this.vmCount = 0;
        def(value, '__ob__', this);
        if (Array.isArray(value)) {
            if (hasProto) {
                protoAugment(value, arrayMethods);
            } else {
                copyAugment(value, arrayMethods, arrayKeys);
            }
            this.observeArray(value);
        } else {
            this.walk(value);
        }
    };

    /**
     * Walk through all properties and convert them into
     * getter/setters. This method should only be called when
     * value type is Object.
     */
    Observer.prototype.walk = function walk (obj) {
        var keys = Object.keys(obj);
        for (var i = 0; i < keys.length; i++) {
            defineReactive$$1(obj, keys[i]);
        }
    };

    /**
     * Observe a list of Array items.
     */
    Observer.prototype.observeArray = function observeArray (items) {
        for (var i = 0, l = items.length; i < l; i++) {
            observe(items[i]);
        }
    };

    // helpers

    /**
     * Augment a target Object or Array by intercepting
     * the prototype chain using __proto__
     */
    function protoAugment (target, src) {
        /* eslint-disable no-proto */
        target.__proto__ = src;
        /* eslint-enable no-proto */
    }

    /**
     * Augment a target Object or Array by defining
     * hidden properties.
     */
    /* istanbul ignore next */
    function copyAugment (target, src, keys) {
        for (var i = 0, l = keys.length; i < l; i++) {
            var key = keys[i];
            def(target, key, src[key]);
        }
    }

    /**
     * Attempt to create an observer instance for a value,
     * returns the new observer if successfully observed,
     * or the existing observer if the value already has one.
     */
    function observe (value, asRootData) {
        if (!isObject(value) || value instanceof VNode) {
            return
        }
        var ob;
        if (hasOwn(value, '__ob__') && value.__ob__ instanceof Observer) {
            ob = value.__ob__;
        } else if (
            shouldObserve &&
            !isServerRendering() &&
            (Array.isArray(value) || isPlainObject(value)) &&
            Object.isExtensible(value) &&
            !value._isVue
        ) {
            ob = new Observer(value);
        }
        if (asRootData && ob) {
            ob.vmCount++;
        }
        return ob
    }

    /**
     * Define a reactive property on an Object.
     */
    function defineReactive$$1 (
        obj,
        key,
        val,
        customSetter,
        shallow
    ) {
        var dep = new Dep();

        var property = Object.getOwnPropertyDescriptor(obj, key);
        if (property && property.configurable === false) {
            return
        }

        // cater for pre-defined getter/setters
        var getter = property && property.get;
        var setter = property && property.set;
        if ((!getter || setter) && arguments.length === 2) {
            val = obj[key];
        }

        var childOb = !shallow && observe(val);
        Object.defineProperty(obj, key, {
            enumerable: true,
            configurable: true,
            get: function reactiveGetter () {
                var value = getter ? getter.call(obj) : val;
                if (Dep.target) {
                    dep.depend();
                    if (childOb) {
                        childOb.dep.depend();
                        if (Array.isArray(value)) {
                            dependArray(value);
                        }
                    }
                }
                return value
            },
            set: function reactiveSetter (newVal) {
                var value = getter ? getter.call(obj) : val;
                /* eslint-disable no-self-compare */
                if (newVal === value || (newVal !== newVal && value !== value)) {
                    return
                }
                /* eslint-enable no-self-compare */
                if (customSetter) {
                    customSetter();
                }
                // #7981: for accessor properties without setter
                if (getter && !setter) { return }
                if (setter) {
                    setter.call(obj, newVal);
                } else {
                    val = newVal;
                }
                childOb = !shallow && observe(newVal);
                dep.notify();
            }
        });
    }

    /**
     * Set a property on an object. Adds the new property and
     * triggers change notification if the property doesn't
     * already exist.
     */
    function set (target, key, val) {
        if (isUndef(target) || isPrimitive(target)
        ) {
            warn(("Cannot set reactive property on undefined, null, or primitive value: " + ((target))));
        }
        if (Array.isArray(target) && isValidArrayIndex(key)) {
            target.length = Math.max(target.length, key);
            target.splice(key, 1, val);
            return val
        }
        if (key in target && !(key in Object.prototype)) {
            target[key] = val;
            return val
        }
        var ob = (target).__ob__;
        if (target._isVue || (ob && ob.vmCount)) {
            warn(
                'Avoid adding reactive properties to a Vue instance or its root $data ' +
                'at runtime - declare it upfront in the data option.'
            );
            return val
        }
        if (!ob) {
            target[key] = val;
            return val
        }
        defineReactive$$1(ob.value, key, val);
        ob.dep.notify();
        return val
    }

    /**
     * Delete a property and trigger change if necessary.
     */
    function del (target, key) {
        if (isUndef(target) || isPrimitive(target)
        ) {
            warn(("Cannot delete reactive property on undefined, null, or primitive value: " + ((target))));
        }
        if (Array.isArray(target) && isValidArrayIndex(key)) {
            target.splice(key, 1);
            return
        }
        var ob = (target).__ob__;
        if (target._isVue || (ob && ob.vmCount)) {
            warn(
                'Avoid deleting properties on a Vue instance or its root $data ' +
                '- just set it to null.'
            );
            return
        }
        if (!hasOwn(target, key)) {
            return
        }
        delete target[key];
        if (!ob) {
            return
        }
        ob.dep.notify();
    }

    /**
     * Collect dependencies on array elements when the array is touched, since
     * we cannot intercept array element access like property getters.
     */
    function dependArray (value) {
        for (var e = (void 0), i = 0, l = value.length; i < l; i++) {
            e = value[i];
            e && e.__ob__ && e.__ob__.dep.depend();
            if (Array.isArray(e)) {
                dependArray(e);
            }
        }
    }

    /*  */

    /**
     * Option overwriting strategies are functions that handle
     * how to merge a parent option value and a child option
     * value into the final value.
     */
    var strats = config.optionMergeStrategies;

    /**
     * Options with restrictions
     */
    {
        strats.el = strats.propsData = function (parent, child, vm, key) {
            if (!vm) {
                warn(
                    "option \"" + key + "\" can only be used during instance " +
                    'creation with the `new` keyword.'
                );
            }
            return defaultStrat(parent, child)
        };
    }

    /**
     * Helper that recursively merges two data objects together.
     */
    function mergeData (to, from) {
        if (!from) { return to }
        var key, toVal, fromVal;

        var keys = hasSymbol
            ? Reflect.ownKeys(from)
            : Object.keys(from);

        for (var i = 0; i < keys.length; i++) {
            key = keys[i];
            // in case the object is already observed...
            if (key === '__ob__') { continue }
            toVal = to[key];
            fromVal = from[key];
            if (!hasOwn(to, key)) {
                set(to, key, fromVal);
            } else if (
                toVal !== fromVal &&
                isPlainObject(toVal) &&
                isPlainObject(fromVal)
            ) {
                mergeData(toVal, fromVal);
            }
        }
        return to
    }

    /**
     * Data
     */
    function mergeDataOrFn (
        parentVal,
        childVal,
        vm
    ) {
        if (!vm) {
            // in a Vue.extend merge, both should be functions
            if (!childVal) {
                return parentVal
            }
            if (!parentVal) {
                return childVal
            }
            // when parentVal & childVal are both present,
            // we need to return a function that returns the
            // merged result of both functions... no need to
            // check if parentVal is a function here because
            // it has to be a function to pass previous merges.
            return function mergedDataFn () {
                return mergeData(
                    typeof childVal === 'function' ? childVal.call(this, this) : childVal,
                    typeof parentVal === 'function' ? parentVal.call(this, this) : parentVal
                )
            }
        } else {
            return function mergedInstanceDataFn () {
                // instance merge
                var instanceData = typeof childVal === 'function'
                    ? childVal.call(vm, vm)
                    : childVal;
                var defaultData = typeof parentVal === 'function'
                    ? parentVal.call(vm, vm)
                    : parentVal;
                if (instanceData) {
                    return mergeData(instanceData, defaultData)
                } else {
                    return defaultData
                }
            }
        }
    }

    strats.data = function (
        parentVal,
        childVal,
        vm
    ) {
        if (!vm) {
            if (childVal && typeof childVal !== 'function') {
                warn(
                    'The "data" option should be a function ' +
                    'that returns a per-instance value in component ' +
                    'definitions.',
                    vm
                );

                return parentVal
            }
            return mergeDataOrFn(parentVal, childVal)
        }

        return mergeDataOrFn(parentVal, childVal, vm)
    };

    /**
     * Hooks and props are merged as arrays.
     */
    function mergeHook (
        parentVal,
        childVal
    ) {
        var res = childVal
            ? parentVal
            ? parentVal.concat(childVal)
            : Array.isArray(childVal)
            ? childVal
            : [childVal]
            : parentVal;
        return res
            ? dedupeHooks(res)
            : res
    }

    function dedupeHooks (hooks) {
        var res = [];
        for (var i = 0; i < hooks.length; i++) {
            if (res.indexOf(hooks[i]) === -1) {
                res.push(hooks[i]);
            }
        }
        return res
    }

    LIFECYCLE_HOOKS.forEach(function (hook) {
        strats[hook] = mergeHook;
    });

    /**
     * Assets
     *
     * When a vm is present (instance creation), we need to do
     * a three-way merge between constructor options, instance
     * options and parent options.
     */
    function mergeAssets (
        parentVal,
        childVal,
        vm,
        key
    ) {
        var res = Object.create(parentVal || null);
        if (childVal) {
            assertObjectType(key, childVal, vm);
            return extend(res, childVal)
        } else {
            return res
        }
    }

    ASSET_TYPES.forEach(function (type) {
        strats[type + 's'] = mergeAssets;
    });

    /**
     * Watchers.
     *
     * Watchers hashes should not overwrite one
     * another, so we merge them as arrays.
     */
    strats.watch = function (
        parentVal,
        childVal,
        vm,
        key
    ) {
        // work around Firefox's Object.prototype.watch...
        if (parentVal === nativeWatch) { parentVal = undefined; }
        if (childVal === nativeWatch) { childVal = undefined; }
        /* istanbul ignore if */
        if (!childVal) { return Object.create(parentVal || null) }
        {
            assertObjectType(key, childVal, vm);
        }
        if (!parentVal) { return childVal }
        var ret = {};
        extend(ret, parentVal);
        for (var key$1 in childVal) {
            var parent = ret[key$1];
            var child = childVal[key$1];
            if (parent && !Array.isArray(parent)) {
                parent = [parent];
            }
            ret[key$1] = parent
                ? parent.concat(child)
                : Array.isArray(child) ? child : [child];
        }
        return ret
    };

    /**
     * Other object hashes.
     */
    strats.props =
        strats.methods =
            strats.inject =
                strats.computed = function (
                    parentVal,
                    childVal,
                    vm,
                    key
                ) {
                    if (childVal && "development" !== 'production') {
                        assertObjectType(key, childVal, vm);
                    }
                    if (!parentVal) { return childVal }
                    var ret = Object.create(null);
                    extend(ret, parentVal);
                    if (childVal) { extend(ret, childVal); }
                    return ret
                };
    strats.provide = mergeDataOrFn;

    /**
     * Default strategy.
     */
    var defaultStrat = function (parentVal, childVal) {
        return childVal === undefined
            ? parentVal
            : childVal
    };

    /**
     * Validate component names
     */
    function checkComponents (options) {
        for (var key in options.components) {
            validateComponentName(key);
        }
    }

    function validateComponentName (name) {
        if (!new RegExp(("^[a-zA-Z][\\-\\.0-9_" + (unicodeRegExp.source) + "]*$")).test(name)) {
            warn(
                'Invalid component name: "' + name + '". Component names ' +
                'should conform to valid custom element name in html5 specification.'
            );
        }
        if (isBuiltInTag(name) || config.isReservedTag(name)) {
            warn(
                'Do not use built-in or reserved HTML elements as component ' +
                'id: ' + name
            );
        }
    }

    /**
     * Ensure all props option syntax are normalized into the
     * Object-based format.
     */
    function normalizeProps (options, vm) {
        var props = options.props;
        if (!props) { return }
        var res = {};
        var i, val, name;
        if (Array.isArray(props)) {
            i = props.length;
            while (i--) {
                val = props[i];
                if (typeof val === 'string') {
                    name = camelize(val);
                    res[name] = { type: null };
                } else {
                    warn('props must be strings when using array syntax.');
                }
            }
        } else if (isPlainObject(props)) {
            for (var key in props) {
                val = props[key];
                name = camelize(key);
                res[name] = isPlainObject(val)
                    ? val
                    : { type: val };
            }
        } else {
            warn(
                "Invalid value for option \"props\": expected an Array or an Object, " +
                "but got " + (toRawType(props)) + ".",
                vm
            );
        }
        options.props = res;
    }

    /**
     * Normalize all injections into Object-based format
     */
    function normalizeInject (options, vm) {
        var inject = options.inject;
        if (!inject) { return }
        var normalized = options.inject = {};
        if (Array.isArray(inject)) {
            for (var i = 0; i < inject.length; i++) {
                normalized[inject[i]] = { from: inject[i] };
            }
        } else if (isPlainObject(inject)) {
            for (var key in inject) {
                var val = inject[key];
                normalized[key] = isPlainObject(val)
                    ? extend({ from: key }, val)
                    : { from: val };
            }
        } else {
            warn(
                "Invalid value for option \"inject\": expected an Array or an Object, " +
                "but got " + (toRawType(inject)) + ".",
                vm
            );
        }
    }

    /**
     * Normalize raw function directives into object format.
     */
    function normalizeDirectives (options) {
        var dirs = options.directives;
        if (dirs) {
            for (var key in dirs) {
                var def$$1 = dirs[key];
                if (typeof def$$1 === 'function') {
                    dirs[key] = { bind: def$$1, update: def$$1 };
                }
            }
        }
    }

    function assertObjectType (name, value, vm) {
        if (!isPlainObject(value)) {
            warn(
                "Invalid value for option \"" + name + "\": expected an Object, " +
                "but got " + (toRawType(value)) + ".",
                vm
            );
        }
    }

    /**
     * Merge two option objects into a new one.
     * Core utility used in both instantiation and inheritance.
     */
    function mergeOptions (
        parent,
        child,
        vm
    ) {
        {
            checkComponents(child);
        }

        if (typeof child === 'function') {
            child = child.options;
        }

        normalizeProps(child, vm);
        normalizeInject(child, vm);
        normalizeDirectives(child);

        // Apply extends and mixins on the child options,
        // but only if it is a raw options object that isn't
        // the result of another mergeOptions call.
        // Only merged options has the _base property.
        if (!child._base) {
            if (child.extends) {
                parent = mergeOptions(parent, child.extends, vm);
            }
            if (child.mixins) {
                for (var i = 0, l = child.mixins.length; i < l; i++) {
                    parent = mergeOptions(parent, child.mixins[i], vm);
                }
            }
        }

        var options = {};
        var key;
        for (key in parent) {
            mergeField(key);
        }
        for (key in child) {
            if (!hasOwn(parent, key)) {
                mergeField(key);
            }
        }
        function mergeField (key) {
            var strat = strats[key] || defaultStrat;
            options[key] = strat(parent[key], child[key], vm, key);
        }
        return options
    }

    /**
     * Resolve an asset.
     * This function is used because child instances need access
     * to assets defined in its ancestor chain.
     */
    function resolveAsset (
        options,
        type,
        id,
        warnMissing
    ) {
        /* istanbul ignore if */
        if (typeof id !== 'string') {
            return
        }
        var assets = options[type];
        // check local registration variations first
        if (hasOwn(assets, id)) { return assets[id] }
        var camelizedId = camelize(id);
        if (hasOwn(assets, camelizedId)) { return assets[camelizedId] }
        var PascalCaseId = capitalize(camelizedId);
        if (hasOwn(assets, PascalCaseId)) { return assets[PascalCaseId] }
        // fallback to prototype chain
        var res = assets[id] || assets[camelizedId] || assets[PascalCaseId];
        if (warnMissing && !res) {
            warn(
                'Failed to resolve ' + type.slice(0, -1) + ': ' + id,
                options
            );
        }
        return res
    }

    /*  */



    function validateProp (
        key,
        propOptions,
        propsData,
        vm
    ) {
        var prop = propOptions[key];
        var absent = !hasOwn(propsData, key);
        var value = propsData[key];
        // boolean casting
        var booleanIndex = getTypeIndex(Boolean, prop.type);
        if (booleanIndex > -1) {
            if (absent && !hasOwn(prop, 'default')) {
                value = false;
            } else if (value === '' || value === hyphenate(key)) {
                // only cast empty string / same name to boolean if
                // boolean has higher priority
                var stringIndex = getTypeIndex(String, prop.type);
                if (stringIndex < 0 || booleanIndex < stringIndex) {
                    value = true;
                }
            }
        }
        // check default value
        if (value === undefined) {
            value = getPropDefaultValue(vm, prop, key);
            // since the default value is a fresh copy,
            // make sure to observe it.
            var prevShouldObserve = shouldObserve;
            toggleObserving(true);
            observe(value);
            toggleObserving(prevShouldObserve);
        }
        {
            assertProp(prop, key, value, vm, absent);
        }
        return value
    }

    /**
     * Get the default value of a prop.
     */
    function getPropDefaultValue (vm, prop, key) {
        // no default, return undefined
        if (!hasOwn(prop, 'default')) {
            return undefined
        }
        var def = prop.default;
        // warn against non-factory defaults for Object & Array
        if (isObject(def)) {
            warn(
                'Invalid default value for prop "' + key + '": ' +
                'Props with type Object/Array must use a factory function ' +
                'to return the default value.',
                vm
            );
        }
        // the raw prop value was also undefined from previous render,
        // return previous default value to avoid unnecessary watcher trigger
        if (vm && vm.$options.propsData &&
            vm.$options.propsData[key] === undefined &&
            vm._props[key] !== undefined
        ) {
            return vm._props[key]
        }
        // call factory function for non-Function types
        // a value is Function if its prototype is function even across different execution context
        return typeof def === 'function' && getType(prop.type) !== 'Function'
            ? def.call(vm)
            : def
    }

    /**
     * Assert whether a prop is valid.
     */
    function assertProp (
        prop,
        name,
        value,
        vm,
        absent
    ) {
        if (prop.required && absent) {
            warn(
                'Missing required prop: "' + name + '"',
                vm
            );
            return
        }
        if (value == null && !prop.required) {
            return
        }
        var type = prop.type;
        var valid = !type || type === true;
        var expectedTypes = [];
        if (type) {
            if (!Array.isArray(type)) {
                type = [type];
            }
            for (var i = 0; i < type.length && !valid; i++) {
                var assertedType = assertType(value, type[i]);
                expectedTypes.push(assertedType.expectedType || '');
                valid = assertedType.valid;
            }
        }

        if (!valid) {
            warn(
                getInvalidTypeMessage(name, value, expectedTypes),
                vm
            );
            return
        }
        var validator = prop.validator;
        if (validator) {
            if (!validator(value)) {
                warn(
                    'Invalid prop: custom validator check failed for prop "' + name + '".',
                    vm
                );
            }
        }
    }

    var simpleCheckRE = /^(String|Number|Boolean|Function|Symbol)$/;

    function assertType (value, type) {
        var valid;
        var expectedType = getType(type);
        if (simpleCheckRE.test(expectedType)) {
            var t = typeof value;
            valid = t === expectedType.toLowerCase();
            // for primitive wrapper objects
            if (!valid && t === 'object') {
                valid = value instanceof type;
            }
        } else if (expectedType === 'Object') {
            valid = isPlainObject(value);
        } else if (expectedType === 'Array') {
            valid = Array.isArray(value);
        } else {
            valid = value instanceof type;
        }
        return {
            valid: valid,
            expectedType: expectedType
        }
    }

    /**
     * Use function string name to check built-in types,
     * because a simple equality check will fail when running
     * across different vms / iframes.
     */
    function getType (fn) {
        var match = fn && fn.toString().match(/^\s*function (\w+)/);
        return match ? match[1] : ''
    }

    function isSameType (a, b) {
        return getType(a) === getType(b)
    }

    function getTypeIndex (type, expectedTypes) {
        if (!Array.isArray(expectedTypes)) {
            return isSameType(expectedTypes, type) ? 0 : -1
        }
        for (var i = 0, len = expectedTypes.length; i < len; i++) {
            if (isSameType(expectedTypes[i], type)) {
                return i
            }
        }
        return -1
    }

    function getInvalidTypeMessage (name, value, expectedTypes) {
        var message = "Invalid prop: type check failed for prop \"" + name + "\"." +
            " Expected " + (expectedTypes.map(capitalize).join(', '));
        var expectedType = expectedTypes[0];
        var receivedType = toRawType(value);
        var expectedValue = styleValue(value, expectedType);
        var receivedValue = styleValue(value, receivedType);
        // check if we need to specify expected value
        if (expectedTypes.length === 1 &&
            isExplicable(expectedType) &&
            !isBoolean(expectedType, receivedType)) {
            message += " with value " + expectedValue;
        }
        message += ", got " + receivedType + " ";
        // check if we need to specify received value
        if (isExplicable(receivedType)) {
            message += "with value " + receivedValue + ".";
        }
        return message
    }

    function styleValue (value, type) {
        if (type === 'String') {
            return ("\"" + value + "\"")
        } else if (type === 'Number') {
            return ("" + (Number(value)))
        } else {
            return ("" + value)
        }
    }

    function isExplicable (value) {
        var explicitTypes = ['string', 'number', 'boolean'];
        return explicitTypes.some(function (elem) { return value.toLowerCase() === elem; })
    }

    function isBoolean () {
        var args = [], len = arguments.length;
        while ( len-- ) args[ len ] = arguments[ len ];

        return args.some(function (elem) { return elem.toLowerCase() === 'boolean'; })
    }

    /*  */

    function handleError (err, vm, info) {
        // Deactivate deps tracking while processing error handler to avoid possible infinite rendering.
        // See: https://github.com/vuejs/vuex/issues/1505
        pushTarget();
        try {
            if (vm) {
                var cur = vm;
                while ((cur = cur.$parent)) {
                    var hooks = cur.$options.errorCaptured;
                    if (hooks) {
                        for (var i = 0; i < hooks.length; i++) {
                            try {
                                var capture = hooks[i].call(cur, err, vm, info) === false;
                                if (capture) { return }
                            } catch (e) {
                                globalHandleError(e, cur, 'errorCaptured hook');
                            }
                        }
                    }
                }
            }
            globalHandleError(err, vm, info);
        } finally {
            popTarget();
        }
    }

    function invokeWithErrorHandling (
        handler,
        context,
        args,
        vm,
        info
    ) {
        var res;
        try {
            res = args ? handler.apply(context, args) : handler.call(context);
            if (res && !res._isVue && isPromise(res) && !res._handled) {
                res.catch(function (e) { return handleError(e, vm, info + " (Promise/async)"); });
                // issue #9511
                // avoid catch triggering multiple times when nested calls
                res._handled = true;
            }
        } catch (e) {
            handleError(e, vm, info);
        }
        return res
    }

    function globalHandleError (err, vm, info) {
        if (config.errorHandler) {
            try {
                return config.errorHandler.call(null, err, vm, info)
            } catch (e) {
                // if the user intentionally throws the original error in the handler,
                // do not log it twice
                if (e !== err) {
                    logError(e, null, 'config.errorHandler');
                }
            }
        }
        logError(err, vm, info);
    }

    function logError (err, vm, info) {
        {
            warn(("Error in " + info + ": \"" + (err.toString()) + "\""), vm);
        }
        /* istanbul ignore else */
        if ((inBrowser || inWeex) && typeof console !== 'undefined') {
            console.error(err);
        } else {
            throw err
        }
    }

    /*  */

    var isUsingMicroTask = false;

    var callbacks = [];
    var pending = false;

    function flushCallbacks () {
        pending = false;
        var copies = callbacks.slice(0);
        callbacks.length = 0;
        for (var i = 0; i < copies.length; i++) {
            copies[i]();
        }
    }

    // Here we have async deferring wrappers using microtasks.
    // In 2.5 we used (macro) tasks (in combination with microtasks).
    // However, it has subtle problems when state is changed right before repaint
    // (e.g. #6813, out-in transitions).
    // Also, using (macro) tasks in event handler would cause some weird behaviors
    // that cannot be circumvented (e.g. #7109, #7153, #7546, #7834, #8109).
    // So we now use microtasks everywhere, again.
    // A major drawback of this tradeoff is that there are some scenarios
    // where microtasks have too high a priority and fire in between supposedly
    // sequential events (e.g. #4521, #6690, which have workarounds)
    // or even between bubbling of the same event (#6566).
    var timerFunc;

    // The nextTick behavior leverages the microtask queue, which can be accessed
    // via either native Promise.then or MutationObserver.
    // MutationObserver has wider support, however it is seriously bugged in
    // UIWebView in iOS >= 9.3.3 when triggered in touch event handlers. It
    // completely stops working after triggering a few times... so, if native
    // Promise is available, we will use it:
    /* istanbul ignore next, $flow-disable-line */
    if (typeof Promise !== 'undefined' && isNative(Promise)) {
        var p = Promise.resolve();
        timerFunc = function () {
            p.then(flushCallbacks);
            // In problematic UIWebViews, Promise.then doesn't completely break, but
            // it can get stuck in a weird state where callbacks are pushed into the
            // microtask queue but the queue isn't being flushed, until the browser
            // needs to do some other work, e.g. handle a timer. Therefore we can
            // "force" the microtask queue to be flushed by adding an empty timer.
            if (isIOS) { setTimeout(noop); }
        };
        isUsingMicroTask = true;
    } else if (!isIE && typeof MutationObserver !== 'undefined' && (
            isNative(MutationObserver) ||
                // PhantomJS and iOS 7.x
            MutationObserver.toString() === '[object MutationObserverConstructor]'
        )) {
        // Use MutationObserver where native Promise is not available,
        // e.g. PhantomJS, iOS7, Android 4.4
        // (#6466 MutationObserver is unreliable in IE11)
        var counter = 1;
        var observer = new MutationObserver(flushCallbacks);
        var textNode = document.createTextNode(String(counter));
        observer.observe(textNode, {
            characterData: true
        });
        timerFunc = function () {
            counter = (counter + 1) % 2;
            textNode.data = String(counter);
        };
        isUsingMicroTask = true;
    } else if (typeof setImmediate !== 'undefined' && isNative(setImmediate)) {
        // Fallback to setImmediate.
        // Techinically it leverages the (macro) task queue,
        // but it is still a better choice than setTimeout.
        timerFunc = function () {
            setImmediate(flushCallbacks);
        };
    } else {
        // Fallback to setTimeout.
        timerFunc = function () {
            setTimeout(flushCallbacks, 0);
        };
    }

    function nextTick (cb, ctx) {
        var _resolve;
        callbacks.push(function () {
            if (cb) {
                try {
                    cb.call(ctx);
                } catch (e) {
                    handleError(e, ctx, 'nextTick');
                }
            } else if (_resolve) {
                _resolve(ctx);
            }
        });
        if (!pending) {
            pending = true;
            timerFunc();
        }
        // $flow-disable-line
        if (!cb && typeof Promise !== 'undefined') {
            return new Promise(function (resolve) {
                _resolve = resolve;
            })
        }
    }

    /*  */

    var mark;
    var measure;

    {
        var perf = inBrowser && window.performance;
        /* istanbul ignore if */
        if (
            perf &&
            perf.mark &&
            perf.measure &&
            perf.clearMarks &&
            perf.clearMeasures
        ) {
            mark = function (tag) { return perf.mark(tag); };
            measure = function (name, startTag, endTag) {
                perf.measure(name, startTag, endTag);
                perf.clearMarks(startTag);
                perf.clearMarks(endTag);
                // perf.clearMeasures(name)
            };
        }
    }

    /* not type checking this file because flow doesn't play well with Proxy */

    var initProxy;

    {
        var allowedGlobals = makeMap(
            'Infinity,undefined,NaN,isFinite,isNaN,' +
            'parseFloat,parseInt,decodeURI,decodeURIComponent,encodeURI,encodeURIComponent,' +
            'Math,Number,Date,Array,Object,Boolean,String,RegExp,Map,Set,JSON,Intl,' +
            'require' // for Webpack/Browserify
        );

        var warnNonPresent = function (target, key) {
            warn(
                "Property or method \"" + key + "\" is not defined on the instance but " +
                'referenced during render. Make sure that this property is reactive, ' +
                'either in the data option, or for class-based components, by ' +
                'initializing the property. ' +
                'See: https://vuejs.org/v2/guide/reactivity.html#Declaring-Reactive-Properties.',
                target
            );
        };

        var warnReservedPrefix = function (target, key) {
            warn(
                "Property \"" + key + "\" must be accessed with \"$data." + key + "\" because " +
                'properties starting with "$" or "_" are not proxied in the Vue instance to ' +
                'prevent conflicts with Vue internals' +
                'See: https://vuejs.org/v2/api/#data',
                target
            );
        };

        var hasProxy =
            typeof Proxy !== 'undefined' && isNative(Proxy);

        if (hasProxy) {
            var isBuiltInModifier = makeMap('stop,prevent,self,ctrl,shift,alt,meta,exact');
            config.keyCodes = new Proxy(config.keyCodes, {
                set: function set (target, key, value) {
                    if (isBuiltInModifier(key)) {
                        warn(("Avoid overwriting built-in modifier in config.keyCodes: ." + key));
                        return false
                    } else {
                        target[key] = value;
                        return true
                    }
                }
            });
        }

        var hasHandler = {
            has: function has (target, key) {
                var has = key in target;
                var isAllowed = allowedGlobals(key) ||
                    (typeof key === 'string' && key.charAt(0) === '_' && !(key in target.$data));
                if (!has && !isAllowed) {
                    if (key in target.$data) { warnReservedPrefix(target, key); }
                    else { warnNonPresent(target, key); }
                }
                return has || !isAllowed
            }
        };

        var getHandler = {
            get: function get (target, key) {
                if (typeof key === 'string' && !(key in target)) {
                    if (key in target.$data) { warnReservedPrefix(target, key); }
                    else { warnNonPresent(target, key); }
                }
                return target[key]
            }
        };

        initProxy = function initProxy (vm) {
            if (hasProxy) {
                // determine which proxy handler to use
                var options = vm.$options;
                var handlers = options.render && options.render._withStripped
                    ? getHandler
                    : hasHandler;
                vm._renderProxy = new Proxy(vm, handlers);
            } else {
                vm._renderProxy = vm;
            }
        };
    }

    /*  */

    var seenObjects = new _Set();

    /**
     * Recursively traverse an object to evoke all converted
     * getters, so that every nested property inside the object
     * is collected as a "deep" dependency.
     */
    function traverse (val) {
        _traverse(val, seenObjects);
        seenObjects.clear();
    }

    function _traverse (val, seen) {
        var i, keys;
        var isA = Array.isArray(val);
        if ((!isA && !isObject(val)) || Object.isFrozen(val) || val instanceof VNode) {
            return
        }
        if (val.__ob__) {
            var depId = val.__ob__.dep.id;
            if (seen.has(depId)) {
                return
            }
            seen.add(depId);
        }
        if (isA) {
            i = val.length;
            while (i--) { _traverse(val[i], seen); }
        } else {
            keys = Object.keys(val);
            i = keys.length;
            while (i--) { _traverse(val[keys[i]], seen); }
        }
    }

    /*  */

    var normalizeEvent = cached(function (name) {
        var passive = name.charAt(0) === '&';
        name = passive ? name.slice(1) : name;
        var once$$1 = name.charAt(0) === '~'; // Prefixed last, checked first
        name = once$$1 ? name.slice(1) : name;
        var capture = name.charAt(0) === '!';
        name = capture ? name.slice(1) : name;
        return {
            name: name,
            once: once$$1,
            capture: capture,
            passive: passive
        }
    });

    function createFnInvoker (fns, vm) {
        function invoker () {
            var arguments$1 = arguments;

            var fns = invoker.fns;
            if (Array.isArray(fns)) {
                var cloned = fns.slice();
                for (var i = 0; i < cloned.length; i++) {
                    invokeWithErrorHandling(cloned[i], null, arguments$1, vm, "v-on handler");
                }
            } else {
                // return handler return value for single handlers
                return invokeWithErrorHandling(fns, null, arguments, vm, "v-on handler")
            }
        }
        invoker.fns = fns;
        return invoker
    }

    function updateListeners (
        on,
        oldOn,
        add,
        remove$$1,
        createOnceHandler,
        vm
    ) {
        var name, def$$1, cur, old, event;
        for (name in on) {
            def$$1 = cur = on[name];
            old = oldOn[name];
            event = normalizeEvent(name);
            if (isUndef(cur)) {
                warn(
                    "Invalid handler for event \"" + (event.name) + "\": got " + String(cur),
                    vm
                );
            } else if (isUndef(old)) {
                if (isUndef(cur.fns)) {
                    cur = on[name] = createFnInvoker(cur, vm);
                }
                if (isTrue(event.once)) {
                    cur = on[name] = createOnceHandler(event.name, cur, event.capture);
                }
                add(event.name, cur, event.capture, event.passive, event.params);
            } else if (cur !== old) {
                old.fns = cur;
                on[name] = old;
            }
        }
        for (name in oldOn) {
            if (isUndef(on[name])) {
                event = normalizeEvent(name);
                remove$$1(event.name, oldOn[name], event.capture);
            }
        }
    }

    /*  */

    function mergeVNodeHook (def, hookKey, hook) {
        if (def instanceof VNode) {
            def = def.data.hook || (def.data.hook = {});
        }
        var invoker;
        var oldHook = def[hookKey];

        function wrappedHook () {
            hook.apply(this, arguments);
            // important: remove merged hook to ensure it's called only once
            // and prevent memory leak
            remove(invoker.fns, wrappedHook);
        }

        if (isUndef(oldHook)) {
            // no existing hook
            invoker = createFnInvoker([wrappedHook]);
        } else {
            /* istanbul ignore if */
            if (isDef(oldHook.fns) && isTrue(oldHook.merged)) {
                // already a merged invoker
                invoker = oldHook;
                invoker.fns.push(wrappedHook);
            } else {
                // existing plain hook
                invoker = createFnInvoker([oldHook, wrappedHook]);
            }
        }

        invoker.merged = true;
        def[hookKey] = invoker;
    }

    /*  */

    function extractPropsFromVNodeData (
        data,
        Ctor,
        tag
    ) {
        // we are only extracting raw values here.
        // validation and default values are handled in the child
        // component itself.
        var propOptions = Ctor.options.props;
        if (isUndef(propOptions)) {
            return
        }
        var res = {};
        var attrs = data.attrs;
        var props = data.props;
        if (isDef(attrs) || isDef(props)) {
            for (var key in propOptions) {
                var altKey = hyphenate(key);
                {
                    var keyInLowerCase = key.toLowerCase();
                    if (
                        key !== keyInLowerCase &&
                        attrs && hasOwn(attrs, keyInLowerCase)
                    ) {
                        tip(
                            "Prop \"" + keyInLowerCase + "\" is passed to component " +
                            (formatComponentName(tag || Ctor)) + ", but the declared prop name is" +
                            " \"" + key + "\". " +
                            "Note that HTML attributes are case-insensitive and camelCased " +
                            "props need to use their kebab-case equivalents when using in-DOM " +
                            "templates. You should probably use \"" + altKey + "\" instead of \"" + key + "\"."
                        );
                    }
                }
                checkProp(res, props, key, altKey, true) ||
                checkProp(res, attrs, key, altKey, false);
            }
        }
        return res
    }

    function checkProp (
        res,
        hash,
        key,
        altKey,
        preserve
    ) {
        if (isDef(hash)) {
            if (hasOwn(hash, key)) {
                res[key] = hash[key];
                if (!preserve) {
                    delete hash[key];
                }
                return true
            } else if (hasOwn(hash, altKey)) {
                res[key] = hash[altKey];
                if (!preserve) {
                    delete hash[altKey];
                }
                return true
            }
        }
        return false
    }

    /*  */

    // The template compiler attempts to minimize the need for normalization by
    // statically analyzing the template at compile time.
    //
    // For plain HTML markup, normalization can be completely skipped because the
    // generated render function is guaranteed to return Array<VNode>. There are
    // two cases where extra normalization is needed:

    // 1. When the children contains components - because a functional component
    // may return an Array instead of a single root. In this case, just a simple
    // normalization is needed - if any child is an Array, we flatten the whole
    // thing with Array.prototype.concat. It is guaranteed to be only 1-level deep
    // because functional components already normalize their own children.
    function simpleNormalizeChildren (children) {
        for (var i = 0; i < children.length; i++) {
            if (Array.isArray(children[i])) {
                return Array.prototype.concat.apply([], children)
            }
        }
        return children
    }

    // 2. When the children contains constructs that always generated nested Arrays,
    // e.g. <template>, <slot>, v-for, or when the children is provided by user
    // with hand-written render functions / JSX. In such cases a full normalization
    // is needed to cater to all possible types of children values.
    function normalizeChildren (children) {
        return isPrimitive(children)
            ? [createTextVNode(children)]
            : Array.isArray(children)
            ? normalizeArrayChildren(children)
            : undefined
    }

    function isTextNode (node) {
        return isDef(node) && isDef(node.text) && isFalse(node.isComment)
    }

    function normalizeArrayChildren (children, nestedIndex) {
        var res = [];
        var i, c, lastIndex, last;
        for (i = 0; i < children.length; i++) {
            c = children[i];
            if (isUndef(c) || typeof c === 'boolean') { continue }
            lastIndex = res.length - 1;
            last = res[lastIndex];
            //  nested
            if (Array.isArray(c)) {
                if (c.length > 0) {
                    c = normalizeArrayChildren(c, ((nestedIndex || '') + "_" + i));
                    // merge adjacent text nodes
                    if (isTextNode(c[0]) && isTextNode(last)) {
                        res[lastIndex] = createTextVNode(last.text + (c[0]).text);
                        c.shift();
                    }
                    res.push.apply(res, c);
                }
            } else if (isPrimitive(c)) {
                if (isTextNode(last)) {
                    // merge adjacent text nodes
                    // this is necessary for SSR hydration because text nodes are
                    // essentially merged when rendered to HTML strings
                    res[lastIndex] = createTextVNode(last.text + c);
                } else if (c !== '') {
                    // convert primitive to vnode
                    res.push(createTextVNode(c));
                }
            } else {
                if (isTextNode(c) && isTextNode(last)) {
                    // merge adjacent text nodes
                    res[lastIndex] = createTextVNode(last.text + c.text);
                } else {
                    // default key for nested array children (likely generated by v-for)
                    if (isTrue(children._isVList) &&
                        isDef(c.tag) &&
                        isUndef(c.key) &&
                        isDef(nestedIndex)) {
                        c.key = "__vlist" + nestedIndex + "_" + i + "__";
                    }
                    res.push(c);
                }
            }
        }
        return res
    }

    /*  */

    function initProvide (vm) {
        var provide = vm.$options.provide;
        if (provide) {
            vm._provided = typeof provide === 'function'
                ? provide.call(vm)
                : provide;
        }
    }

    function initInjections (vm) {
        var result = resolveInject(vm.$options.inject, vm);
        if (result) {
            toggleObserving(false);
            Object.keys(result).forEach(function (key) {
                /* istanbul ignore else */
                {
                    defineReactive$$1(vm, key, result[key], function () {
                        warn(
                            "Avoid mutating an injected value directly since the changes will be " +
                            "overwritten whenever the provided component re-renders. " +
                            "injection being mutated: \"" + key + "\"",
                            vm
                        );
                    });
                }
            });
            toggleObserving(true);
        }
    }

    function resolveInject (inject, vm) {
        if (inject) {
            // inject is :any because flow is not smart enough to figure out cached
            var result = Object.create(null);
            var keys = hasSymbol
                ? Reflect.ownKeys(inject)
                : Object.keys(inject);

            for (var i = 0; i < keys.length; i++) {
                var key = keys[i];
                // #6574 in case the inject object is observed...
                if (key === '__ob__') { continue }
                var provideKey = inject[key].from;
                var source = vm;
                while (source) {
                    if (source._provided && hasOwn(source._provided, provideKey)) {
                        result[key] = source._provided[provideKey];
                        break
                    }
                    source = source.$parent;
                }
                if (!source) {
                    if ('default' in inject[key]) {
                        var provideDefault = inject[key].default;
                        result[key] = typeof provideDefault === 'function'
                            ? provideDefault.call(vm)
                            : provideDefault;
                    } else {
                        warn(("Injection \"" + key + "\" not found"), vm);
                    }
                }
            }
            return result
        }
    }

    /*  */



    /**
     * Runtime helper for resolving raw children VNodes into a slot object.
     */
    function resolveSlots (
        children,
        context
    ) {
        if (!children || !children.length) {
            return {}
        }
        var slots = {};
        for (var i = 0, l = children.length; i < l; i++) {
            var child = children[i];
            var data = child.data;
            // remove slot attribute if the node is resolved as a Vue slot node
            if (data && data.attrs && data.attrs.slot) {
                delete data.attrs.slot;
            }
            // named slots should only be respected if the vnode was rendered in the
            // same context.
            if ((child.context === context || child.fnContext === context) &&
                data && data.slot != null
            ) {
                var name = data.slot;
                var slot = (slots[name] || (slots[name] = []));
                if (child.tag === 'template') {
                    slot.push.apply(slot, child.children || []);
                } else {
                    slot.push(child);
                }
            } else {
                (slots.default || (slots.default = [])).push(child);
            }
        }
        // ignore slots that contains only whitespace
        for (var name$1 in slots) {
            if (slots[name$1].every(isWhitespace)) {
                delete slots[name$1];
            }
        }
        return slots
    }

    function isWhitespace (node) {
        return (node.isComment && !node.asyncFactory) || node.text === ' '
    }

    /*  */

    function normalizeScopedSlots (
        slots,
        normalSlots,
        prevSlots
    ) {
        var res;
        var hasNormalSlots = Object.keys(normalSlots).length > 0;
        var isStable = slots ? !!slots.$stable : !hasNormalSlots;
        var key = slots && slots.$key;
        if (!slots) {
            res = {};
        } else if (slots._normalized) {
            // fast path 1: child component re-render only, parent did not change
            return slots._normalized
        } else if (
            isStable &&
            prevSlots &&
            prevSlots !== emptyObject &&
            key === prevSlots.$key &&
            !hasNormalSlots &&
            !prevSlots.$hasNormal
        ) {
            // fast path 2: stable scoped slots w/ no normal slots to proxy,
            // only need to normalize once
            return prevSlots
        } else {
            res = {};
            for (var key$1 in slots) {
                if (slots[key$1] && key$1[0] !== '$') {
                    res[key$1] = normalizeScopedSlot(normalSlots, key$1, slots[key$1]);
                }
            }
        }
        // expose normal slots on scopedSlots
        for (var key$2 in normalSlots) {
            if (!(key$2 in res)) {
                res[key$2] = proxyNormalSlot(normalSlots, key$2);
            }
        }
        // avoriaz seems to mock a non-extensible $scopedSlots object
        // and when that is passed down this would cause an error
        if (slots && Object.isExtensible(slots)) {
            (slots)._normalized = res;
        }
        def(res, '$stable', isStable);
        def(res, '$key', key);
        def(res, '$hasNormal', hasNormalSlots);
        return res
    }

    function normalizeScopedSlot(normalSlots, key, fn) {
        var normalized = function () {
            var res = arguments.length ? fn.apply(null, arguments) : fn({});
            res = res && typeof res === 'object' && !Array.isArray(res)
                ? [res] // single vnode
                : normalizeChildren(res);
            return res && (
                res.length === 0 ||
                (res.length === 1 && res[0].isComment) // #9658
            ) ? undefined
                : res
        };
        // this is a slot using the new v-slot syntax without scope. although it is
        // compiled as a scoped slot, render fn users would expect it to be present
        // on this.$slots because the usage is semantically a normal slot.
        if (fn.proxy) {
            Object.defineProperty(normalSlots, key, {
                get: normalized,
                enumerable: true,
                configurable: true
            });
        }
        return normalized
    }

    function proxyNormalSlot(slots, key) {
        return function () { return slots[key]; }
    }

    /*  */

    /**
     * Runtime helper for rendering v-for lists.
     */
    function renderList (
        val,
        render
    ) {
        var ret, i, l, keys, key;
        if (Array.isArray(val) || typeof val === 'string') {
            ret = new Array(val.length);
            for (i = 0, l = val.length; i < l; i++) {
                ret[i] = render(val[i], i);
            }
        } else if (typeof val === 'number') {
            ret = new Array(val);
            for (i = 0; i < val; i++) {
                ret[i] = render(i + 1, i);
            }
        } else if (isObject(val)) {
            if (hasSymbol && val[Symbol.iterator]) {
                ret = [];
                var iterator = val[Symbol.iterator]();
                var result = iterator.next();
                while (!result.done) {
                    ret.push(render(result.value, ret.length));
                    result = iterator.next();
                }
            } else {
                keys = Object.keys(val);
                ret = new Array(keys.length);
                for (i = 0, l = keys.length; i < l; i++) {
                    key = keys[i];
                    ret[i] = render(val[key], key, i);
                }
            }
        }
        if (!isDef(ret)) {
            ret = [];
        }
        (ret)._isVList = true;
        return ret
    }

    /*  */

    /**
     * Runtime helper for rendering <slot>
     */
    function renderSlot (
        name,
        fallback,
        props,
        bindObject
    ) {
        var scopedSlotFn = this.$scopedSlots[name];
        var nodes;
        if (scopedSlotFn) { // scoped slot
            props = props || {};
            if (bindObject) {
                if (!isObject(bindObject)) {
                    warn(
                        'slot v-bind without argument expects an Object',
                        this
                    );
                }
                props = extend(extend({}, bindObject), props);
            }
            nodes = scopedSlotFn(props) || fallback;
        } else {
            nodes = this.$slots[name] || fallback;
        }

        var target = props && props.slot;
        if (target) {
            return this.$createElement('template', { slot: target }, nodes)
        } else {
            return nodes
        }
    }

    /*  */

    /**
     * Runtime helper for resolving filters
     */
    function resolveFilter (id) {
        return resolveAsset(this.$options, 'filters', id, true) || identity
    }

    /*  */

    function isKeyNotMatch (expect, actual) {
        if (Array.isArray(expect)) {
            return expect.indexOf(actual) === -1
        } else {
            return expect !== actual
        }
    }

    /**
     * Runtime helper for checking keyCodes from config.
     * exposed as Vue.prototype._k
     * passing in eventKeyName as last argument separately for backwards compat
     */
    function checkKeyCodes (
        eventKeyCode,
        key,
        builtInKeyCode,
        eventKeyName,
        builtInKeyName
    ) {
        var mappedKeyCode = config.keyCodes[key] || builtInKeyCode;
        if (builtInKeyName && eventKeyName && !config.keyCodes[key]) {
            return isKeyNotMatch(builtInKeyName, eventKeyName)
        } else if (mappedKeyCode) {
            return isKeyNotMatch(mappedKeyCode, eventKeyCode)
        } else if (eventKeyName) {
            return hyphenate(eventKeyName) !== key
        }
    }

    /*  */

    /**
     * Runtime helper for merging v-bind="object" into a VNode's data.
     */
    function bindObjectProps (
        data,
        tag,
        value,
        asProp,
        isSync
    ) {
        if (value) {
            if (!isObject(value)) {
                warn(
                    'v-bind without argument expects an Object or Array value',
                    this
                );
            } else {
                if (Array.isArray(value)) {
                    value = toObject(value);
                }
                var hash;
                var loop = function ( key ) {
                    if (
                        key === 'class' ||
                        key === 'style' ||
                        isReservedAttribute(key)
                    ) {
                        hash = data;
                    } else {
                        var type = data.attrs && data.attrs.type;
                        hash = asProp || config.mustUseProp(tag, type, key)
                            ? data.domProps || (data.domProps = {})
                            : data.attrs || (data.attrs = {});
                    }
                    var camelizedKey = camelize(key);
                    var hyphenatedKey = hyphenate(key);
                    if (!(camelizedKey in hash) && !(hyphenatedKey in hash)) {
                        hash[key] = value[key];

                        if (isSync) {
                            var on = data.on || (data.on = {});
                            on[("update:" + key)] = function ($event) {
                                value[key] = $event;
                            };
                        }
                    }
                };

                for (var key in value) loop( key );
            }
        }
        return data
    }

    /*  */

    /**
     * Runtime helper for rendering static trees.
     */
    function renderStatic (
        index,
        isInFor
    ) {
        var cached = this._staticTrees || (this._staticTrees = []);
        var tree = cached[index];
        // if has already-rendered static tree and not inside v-for,
        // we can reuse the same tree.
        if (tree && !isInFor) {
            return tree
        }
        // otherwise, render a fresh tree.
        tree = cached[index] = this.$options.staticRenderFns[index].call(
            this._renderProxy,
            null,
            this // for render fns generated for functional component templates
        );
        markStatic(tree, ("__static__" + index), false);
        return tree
    }

    /**
     * Runtime helper for v-once.
     * Effectively it means marking the node as static with a unique key.
     */
    function markOnce (
        tree,
        index,
        key
    ) {
        markStatic(tree, ("__once__" + index + (key ? ("_" + key) : "")), true);
        return tree
    }

    function markStatic (
        tree,
        key,
        isOnce
    ) {
        if (Array.isArray(tree)) {
            for (var i = 0; i < tree.length; i++) {
                if (tree[i] && typeof tree[i] !== 'string') {
                    markStaticNode(tree[i], (key + "_" + i), isOnce);
                }
            }
        } else {
            markStaticNode(tree, key, isOnce);
        }
    }

    function markStaticNode (node, key, isOnce) {
        node.isStatic = true;
        node.key = key;
        node.isOnce = isOnce;
    }

    /*  */

    function bindObjectListeners (data, value) {
        if (value) {
            if (!isPlainObject(value)) {
                warn(
                    'v-on without argument expects an Object value',
                    this
                );
            } else {
                var on = data.on = data.on ? extend({}, data.on) : {};
                for (var key in value) {
                    var existing = on[key];
                    var ours = value[key];
                    on[key] = existing ? [].concat(existing, ours) : ours;
                }
            }
        }
        return data
    }

    /*  */

    function resolveScopedSlots (
        fns, // see flow/vnode
        res,
        // the following are added in 2.6
        hasDynamicKeys,
        contentHashKey
    ) {
        res = res || { $stable: !hasDynamicKeys };
        for (var i = 0; i < fns.length; i++) {
            var slot = fns[i];
            if (Array.isArray(slot)) {
                resolveScopedSlots(slot, res, hasDynamicKeys);
            } else if (slot) {
                // marker for reverse proxying v-slot without scope on this.$slots
                if (slot.proxy) {
                    slot.fn.proxy = true;
                }
                res[slot.key] = slot.fn;
            }
        }
        if (contentHashKey) {
            (res).$key = contentHashKey;
        }
        return res
    }

    /*  */

    function bindDynamicKeys (baseObj, values) {
        for (var i = 0; i < values.length; i += 2) {
            var key = values[i];
            if (typeof key === 'string' && key) {
                baseObj[values[i]] = values[i + 1];
            } else if (key !== '' && key !== null) {
                // null is a speical value for explicitly removing a binding
                warn(
                    ("Invalid value for dynamic directive argument (expected string or null): " + key),
                    this
                );
            }
        }
        return baseObj
    }

    // helper to dynamically append modifier runtime markers to event names.
    // ensure only append when value is already string, otherwise it will be cast
    // to string and cause the type check to miss.
    function prependModifier (value, symbol) {
        return typeof value === 'string' ? symbol + value : value
    }

    /*  */

    function installRenderHelpers (target) {
        target._o = markOnce;
        target._n = toNumber;
        target._s = toString;
        target._l = renderList;
        target._t = renderSlot;
        target._q = looseEqual;
        target._i = looseIndexOf;
        target._m = renderStatic;
        target._f = resolveFilter;
        target._k = checkKeyCodes;
        target._b = bindObjectProps;
        target._v = createTextVNode;
        target._e = createEmptyVNode;
        target._u = resolveScopedSlots;
        target._g = bindObjectListeners;
        target._d = bindDynamicKeys;
        target._p = prependModifier;
    }

    /*  */

    function FunctionalRenderContext (
        data,
        props,
        children,
        parent,
        Ctor
    ) {
        var this$1 = this;

        var options = Ctor.options;
        // ensure the createElement function in functional components
        // gets a unique context - this is necessary for correct named slot check
        var contextVm;
        if (hasOwn(parent, '_uid')) {
            contextVm = Object.create(parent);
            // $flow-disable-line
            contextVm._original = parent;
        } else {
            // the context vm passed in is a functional context as well.
            // in this case we want to make sure we are able to get a hold to the
            // real context instance.
            contextVm = parent;
            // $flow-disable-line
            parent = parent._original;
        }
        var isCompiled = isTrue(options._compiled);
        var needNormalization = !isCompiled;

        this.data = data;
        this.props = props;
        this.children = children;
        this.parent = parent;
        this.listeners = data.on || emptyObject;
        this.injections = resolveInject(options.inject, parent);
        this.slots = function () {
            if (!this$1.$slots) {
                normalizeScopedSlots(
                    data.scopedSlots,
                    this$1.$slots = resolveSlots(children, parent)
                );
            }
            return this$1.$slots
        };

        Object.defineProperty(this, 'scopedSlots', ({
            enumerable: true,
            get: function get () {
                return normalizeScopedSlots(data.scopedSlots, this.slots())
            }
        }));

        // support for compiled functional template
        if (isCompiled) {
            // exposing $options for renderStatic()
            this.$options = options;
            // pre-resolve slots for renderSlot()
            this.$slots = this.slots();
            this.$scopedSlots = normalizeScopedSlots(data.scopedSlots, this.$slots);
        }

        if (options._scopeId) {
            this._c = function (a, b, c, d) {
                var vnode = createElement(contextVm, a, b, c, d, needNormalization);
                if (vnode && !Array.isArray(vnode)) {
                    vnode.fnScopeId = options._scopeId;
                    vnode.fnContext = parent;
                }
                return vnode
            };
        } else {
            this._c = function (a, b, c, d) { return createElement(contextVm, a, b, c, d, needNormalization); };
        }
    }

    installRenderHelpers(FunctionalRenderContext.prototype);

    function createFunctionalComponent (
        Ctor,
        propsData,
        data,
        contextVm,
        children
    ) {
        var options = Ctor.options;
        var props = {};
        var propOptions = options.props;
        if (isDef(propOptions)) {
            for (var key in propOptions) {
                props[key] = validateProp(key, propOptions, propsData || emptyObject);
            }
        } else {
            if (isDef(data.attrs)) { mergeProps(props, data.attrs); }
            if (isDef(data.props)) { mergeProps(props, data.props); }
        }

        var renderContext = new FunctionalRenderContext(
            data,
            props,
            children,
            contextVm,
            Ctor
        );

        var vnode = options.render.call(null, renderContext._c, renderContext);

        if (vnode instanceof VNode) {
            return cloneAndMarkFunctionalResult(vnode, data, renderContext.parent, options, renderContext)
        } else if (Array.isArray(vnode)) {
            var vnodes = normalizeChildren(vnode) || [];
            var res = new Array(vnodes.length);
            for (var i = 0; i < vnodes.length; i++) {
                res[i] = cloneAndMarkFunctionalResult(vnodes[i], data, renderContext.parent, options, renderContext);
            }
            return res
        }
    }

    function cloneAndMarkFunctionalResult (vnode, data, contextVm, options, renderContext) {
        // #7817 clone node before setting fnContext, otherwise if the node is reused
        // (e.g. it was from a cached normal slot) the fnContext causes named slots
        // that should not be matched to match.
        var clone = cloneVNode(vnode);
        clone.fnContext = contextVm;
        clone.fnOptions = options;
        {
            (clone.devtoolsMeta = clone.devtoolsMeta || {}).renderContext = renderContext;
        }
        if (data.slot) {
            (clone.data || (clone.data = {})).slot = data.slot;
        }
        return clone
    }

    function mergeProps (to, from) {
        for (var key in from) {
            to[camelize(key)] = from[key];
        }
    }

    /*  */

    /*  */

    /*  */

    /*  */

    // inline hooks to be invoked on component VNodes during patch
    var componentVNodeHooks = {
        init: function init (vnode, hydrating) {
            if (
                vnode.componentInstance &&
                !vnode.componentInstance._isDestroyed &&
                vnode.data.keepAlive
            ) {
                // kept-alive components, treat as a patch
                var mountedNode = vnode; // work around flow
                componentVNodeHooks.prepatch(mountedNode, mountedNode);
            } else {
                var child = vnode.componentInstance = createComponentInstanceForVnode(
                    vnode,
                    activeInstance
                );
                child.$mount(hydrating ? vnode.elm : undefined, hydrating);
            }
        },

        prepatch: function prepatch (oldVnode, vnode) {
            var options = vnode.componentOptions;
            var child = vnode.componentInstance = oldVnode.componentInstance;
            updateChildComponent(
                child,
                options.propsData, // updated props
                options.listeners, // updated listeners
                vnode, // new parent vnode
                options.children // new children
            );
        },

        insert: function insert (vnode) {
            var context = vnode.context;
            var componentInstance = vnode.componentInstance;
            if (!componentInstance._isMounted) {
                componentInstance._isMounted = true;
                callHook(componentInstance, 'mounted');
            }
            if (vnode.data.keepAlive) {
                if (context._isMounted) {
                    // vue-router#1212
                    // During updates, a kept-alive component's child components may
                    // change, so directly walking the tree here may call activated hooks
                    // on incorrect children. Instead we push them into a queue which will
                    // be processed after the whole patch process ended.
                    queueActivatedComponent(componentInstance);
                } else {
                    activateChildComponent(componentInstance, true /* direct */);
                }
            }
        },

        destroy: function destroy (vnode) {
            var componentInstance = vnode.componentInstance;
            if (!componentInstance._isDestroyed) {
                if (!vnode.data.keepAlive) {
                    componentInstance.$destroy();
                } else {
                    deactivateChildComponent(componentInstance, true /* direct */);
                }
            }
        }
    };

    var hooksToMerge = Object.keys(componentVNodeHooks);

    function createComponent (
        Ctor,
        data,
        context,
        children,
        tag
    ) {
        if (isUndef(Ctor)) {
            return
        }

        var baseCtor = context.$options._base;

        // plain options object: turn it into a constructor
        if (isObject(Ctor)) {
            Ctor = baseCtor.extend(Ctor);
        }

        // if at this stage it's not a constructor or an async component factory,
        // reject.
        if (typeof Ctor !== 'function') {
            {
                warn(("Invalid Component definition: " + (String(Ctor))), context);
            }
            return
        }

        // async component
        var asyncFactory;
        if (isUndef(Ctor.cid)) {
            asyncFactory = Ctor;
            Ctor = resolveAsyncComponent(asyncFactory, baseCtor);
            if (Ctor === undefined) {
                // return a placeholder node for async component, which is rendered
                // as a comment node but preserves all the raw information for the node.
                // the information will be used for async server-rendering and hydration.
                return createAsyncPlaceholder(
                    asyncFactory,
                    data,
                    context,
                    children,
                    tag
                )
            }
        }

        data = data || {};

        // resolve constructor options in case global mixins are applied after
        // component constructor creation
        resolveConstructorOptions(Ctor);

        // transform component v-model data into props & events
        if (isDef(data.model)) {
            transformModel(Ctor.options, data);
        }

        // extract props
        var propsData = extractPropsFromVNodeData(data, Ctor, tag);

        // functional component
        if (isTrue(Ctor.options.functional)) {
            return createFunctionalComponent(Ctor, propsData, data, context, children)
        }

        // extract listeners, since these needs to be treated as
        // child component listeners instead of DOM listeners
        var listeners = data.on;
        // replace with listeners with .native modifier
        // so it gets processed during parent component patch.
        data.on = data.nativeOn;

        if (isTrue(Ctor.options.abstract)) {
            // abstract components do not keep anything
            // other than props & listeners & slot

            // work around flow
            var slot = data.slot;
            data = {};
            if (slot) {
                data.slot = slot;
            }
        }

        // install component management hooks onto the placeholder node
        installComponentHooks(data);

        // return a placeholder vnode
        var name = Ctor.options.name || tag;
        var vnode = new VNode(
            ("vue-component-" + (Ctor.cid) + (name ? ("-" + name) : '')),
            data, undefined, undefined, undefined, context,
            { Ctor: Ctor, propsData: propsData, listeners: listeners, tag: tag, children: children },
            asyncFactory
        );

        return vnode
    }

    function createComponentInstanceForVnode (
        vnode, // we know it's MountedComponentVNode but flow doesn't
        parent // activeInstance in lifecycle state
    ) {
        var options = {
            _isComponent: true,
            _parentVnode: vnode,
            parent: parent
        };
        // check inline-template render functions
        var inlineTemplate = vnode.data.inlineTemplate;
        if (isDef(inlineTemplate)) {
            options.render = inlineTemplate.render;
            options.staticRenderFns = inlineTemplate.staticRenderFns;
        }
        return new vnode.componentOptions.Ctor(options)
    }

    function installComponentHooks (data) {
        var hooks = data.hook || (data.hook = {});
        for (var i = 0; i < hooksToMerge.length; i++) {
            var key = hooksToMerge[i];
            var existing = hooks[key];
            var toMerge = componentVNodeHooks[key];
            if (existing !== toMerge && !(existing && existing._merged)) {
                hooks[key] = existing ? mergeHook$1(toMerge, existing) : toMerge;
            }
        }
    }

    function mergeHook$1 (f1, f2) {
        var merged = function (a, b) {
            // flow complains about extra args which is why we use any
            f1(a, b);
            f2(a, b);
        };
        merged._merged = true;
        return merged
    }

    // transform component v-model info (value and callback) into
    // prop and event handler respectively.
    function transformModel (options, data) {
        var prop = (options.model && options.model.prop) || 'value';
        var event = (options.model && options.model.event) || 'input'
            ;(data.attrs || (data.attrs = {}))[prop] = data.model.value;
        var on = data.on || (data.on = {});
        var existing = on[event];
        var callback = data.model.callback;
        if (isDef(existing)) {
            if (
                Array.isArray(existing)
                    ? existing.indexOf(callback) === -1
                    : existing !== callback
            ) {
                on[event] = [callback].concat(existing);
            }
        } else {
            on[event] = callback;
        }
    }

    /*  */

    var SIMPLE_NORMALIZE = 1;
    var ALWAYS_NORMALIZE = 2;

    // wrapper function for providing a more flexible interface
    // without getting yelled at by flow
    function createElement (
        context,
        tag,
        data,
        children,
        normalizationType,
        alwaysNormalize
    ) {
        if (Array.isArray(data) || isPrimitive(data)) {
            normalizationType = children;
            children = data;
            data = undefined;
        }
        if (isTrue(alwaysNormalize)) {
            normalizationType = ALWAYS_NORMALIZE;
        }
        return _createElement(context, tag, data, children, normalizationType)
    }

    function _createElement (
        context,
        tag,
        data,
        children,
        normalizationType
    ) {
        if (isDef(data) && isDef((data).__ob__)) {
            warn(
                "Avoid using observed data object as vnode data: " + (JSON.stringify(data)) + "\n" +
                'Always create fresh vnode data objects in each render!',
                context
            );
            return createEmptyVNode()
        }
        // object syntax in v-bind
        if (isDef(data) && isDef(data.is)) {
            tag = data.is;
        }
        if (!tag) {
            // in case of component :is set to falsy value
            return createEmptyVNode()
        }
        // warn against non-primitive key
        if (isDef(data) && isDef(data.key) && !isPrimitive(data.key)
        ) {
            {
                warn(
                    'Avoid using non-primitive value as key, ' +
                    'use string/number value instead.',
                    context
                );
            }
        }
        // support single function children as default scoped slot
        if (Array.isArray(children) &&
            typeof children[0] === 'function'
        ) {
            data = data || {};
            data.scopedSlots = { default: children[0] };
            children.length = 0;
        }
        if (normalizationType === ALWAYS_NORMALIZE) {
            children = normalizeChildren(children);
        } else if (normalizationType === SIMPLE_NORMALIZE) {
            children = simpleNormalizeChildren(children);
        }
        var vnode, ns;
        if (typeof tag === 'string') {
            var Ctor;
            ns = (context.$vnode && context.$vnode.ns) || config.getTagNamespace(tag);
            if (config.isReservedTag(tag)) {
                // platform built-in elements
                vnode = new VNode(
                    config.parsePlatformTagName(tag), data, children,
                    undefined, undefined, context
                );
            } else if ((!data || !data.pre) && isDef(Ctor = resolveAsset(context.$options, 'components', tag))) {
                // component
                vnode = createComponent(Ctor, data, context, children, tag);
            } else {
                // unknown or unlisted namespaced elements
                // check at runtime because it may get assigned a namespace when its
                // parent normalizes children
                vnode = new VNode(
                    tag, data, children,
                    undefined, undefined, context
                );
            }
        } else {
            // direct component options / constructor
            vnode = createComponent(tag, data, context, children);
        }
        if (Array.isArray(vnode)) {
            return vnode
        } else if (isDef(vnode)) {
            if (isDef(ns)) { applyNS(vnode, ns); }
            if (isDef(data)) { registerDeepBindings(data); }
            return vnode
        } else {
            return createEmptyVNode()
        }
    }

    function applyNS (vnode, ns, force) {
        vnode.ns = ns;
        if (vnode.tag === 'foreignObject') {
            // use default namespace inside foreignObject
            ns = undefined;
            force = true;
        }
        if (isDef(vnode.children)) {
            for (var i = 0, l = vnode.children.length; i < l; i++) {
                var child = vnode.children[i];
                if (isDef(child.tag) && (
                    isUndef(child.ns) || (isTrue(force) && child.tag !== 'svg'))) {
                    applyNS(child, ns, force);
                }
            }
        }
    }

    // ref #5318
    // necessary to ensure parent re-render when deep bindings like :style and
    // :class are used on slot nodes
    function registerDeepBindings (data) {
        if (isObject(data.style)) {
            traverse(data.style);
        }
        if (isObject(data.class)) {
            traverse(data.class);
        }
    }

    /*  */

    function initRender (vm) {
        vm._vnode = null; // the root of the child tree
        vm._staticTrees = null; // v-once cached trees
        var options = vm.$options;
        var parentVnode = vm.$vnode = options._parentVnode; // the placeholder node in parent tree
        var renderContext = parentVnode && parentVnode.context;
        vm.$slots = resolveSlots(options._renderChildren, renderContext);
        vm.$scopedSlots = emptyObject;
        // bind the createElement fn to this instance
        // so that we get proper render context inside it.
        // args order: tag, data, children, normalizationType, alwaysNormalize
        // internal version is used by render functions compiled from templates
        vm._c = function (a, b, c, d) { return createElement(vm, a, b, c, d, false); };
        // normalization is always applied for the public version, used in
        // user-written render functions.
        vm.$createElement = function (a, b, c, d) { return createElement(vm, a, b, c, d, true); };

        // $attrs & $listeners are exposed for easier HOC creation.
        // they need to be reactive so that HOCs using them are always updated
        var parentData = parentVnode && parentVnode.data;

        /* istanbul ignore else */
        {
            defineReactive$$1(vm, '$attrs', parentData && parentData.attrs || emptyObject, function () {
                !isUpdatingChildComponent && warn("$attrs is readonly.", vm);
            }, true);
            defineReactive$$1(vm, '$listeners', options._parentListeners || emptyObject, function () {
                !isUpdatingChildComponent && warn("$listeners is readonly.", vm);
            }, true);
        }
    }

    var currentRenderingInstance = null;

    function renderMixin (Vue) {
        // install runtime convenience helpers
        installRenderHelpers(Vue.prototype);

        Vue.prototype.$nextTick = function (fn) {
            return nextTick(fn, this)
        };

        Vue.prototype._render = function () {
            var vm = this;
            var ref = vm.$options;
            var render = ref.render;
            var _parentVnode = ref._parentVnode;

            if (_parentVnode) {
                vm.$scopedSlots = normalizeScopedSlots(
                    _parentVnode.data.scopedSlots,
                    vm.$slots,
                    vm.$scopedSlots
                );
            }

            // set parent vnode. this allows render functions to have access
            // to the data on the placeholder node.
            vm.$vnode = _parentVnode;
            // render self
            var vnode;
            try {
                // There's no need to maintain a stack becaues all render fns are called
                // separately from one another. Nested component's render fns are called
                // when parent component is patched.
                currentRenderingInstance = vm;
                vnode = render.call(vm._renderProxy, vm.$createElement);
            } catch (e) {
                handleError(e, vm, "render");
                // return error render result,
                // or previous vnode to prevent render error causing blank component
                /* istanbul ignore else */
                if (vm.$options.renderError) {
                    try {
                        vnode = vm.$options.renderError.call(vm._renderProxy, vm.$createElement, e);
                    } catch (e) {
                        handleError(e, vm, "renderError");
                        vnode = vm._vnode;
                    }
                } else {
                    vnode = vm._vnode;
                }
            } finally {
                currentRenderingInstance = null;
            }
            // if the returned array contains only a single node, allow it
            if (Array.isArray(vnode) && vnode.length === 1) {
                vnode = vnode[0];
            }
            // return empty vnode in case the render function errored out
            if (!(vnode instanceof VNode)) {
                if (Array.isArray(vnode)) {
                    warn(
                        'Multiple root nodes returned from render function. Render function ' +
                        'should return a single root node.',
                        vm
                    );
                }
                vnode = createEmptyVNode();
            }
            // set parent
            vnode.parent = _parentVnode;
            return vnode
        };
    }

    /*  */

    function ensureCtor (comp, base) {
        if (
            comp.__esModule ||
            (hasSymbol && comp[Symbol.toStringTag] === 'Module')
        ) {
            comp = comp.default;
        }
        return isObject(comp)
            ? base.extend(comp)
            : comp
    }

    function createAsyncPlaceholder (
        factory,
        data,
        context,
        children,
        tag
    ) {
        var node = createEmptyVNode();
        node.asyncFactory = factory;
        node.asyncMeta = { data: data, context: context, children: children, tag: tag };
        return node
    }

    function resolveAsyncComponent (
        factory,
        baseCtor
    ) {
        if (isTrue(factory.error) && isDef(factory.errorComp)) {
            return factory.errorComp
        }

        if (isDef(factory.resolved)) {
            return factory.resolved
        }

        var owner = currentRenderingInstance;
        if (owner && isDef(factory.owners) && factory.owners.indexOf(owner) === -1) {
            // already pending
            factory.owners.push(owner);
        }

        if (isTrue(factory.loading) && isDef(factory.loadingComp)) {
            return factory.loadingComp
        }

        if (owner && !isDef(factory.owners)) {
            var owners = factory.owners = [owner];
            var sync = true;
            var timerLoading = null;
            var timerTimeout = null

                ;(owner).$on('hook:destroyed', function () { return remove(owners, owner); });

            var forceRender = function (renderCompleted) {
                for (var i = 0, l = owners.length; i < l; i++) {
                    (owners[i]).$forceUpdate();
                }

                if (renderCompleted) {
                    owners.length = 0;
                    if (timerLoading !== null) {
                        clearTimeout(timerLoading);
                        timerLoading = null;
                    }
                    if (timerTimeout !== null) {
                        clearTimeout(timerTimeout);
                        timerTimeout = null;
                    }
                }
            };

            var resolve = once(function (res) {
                // cache resolved
                factory.resolved = ensureCtor(res, baseCtor);
                // invoke callbacks only if this is not a synchronous resolve
                // (async resolves are shimmed as synchronous during SSR)
                if (!sync) {
                    forceRender(true);
                } else {
                    owners.length = 0;
                }
            });

            var reject = once(function (reason) {
                warn(
                    "Failed to resolve async component: " + (String(factory)) +
                    (reason ? ("\nReason: " + reason) : '')
                );
                if (isDef(factory.errorComp)) {
                    factory.error = true;
                    forceRender(true);
                }
            });

            var res = factory(resolve, reject);

            if (isObject(res)) {
                if (isPromise(res)) {
                    // () => Promise
                    if (isUndef(factory.resolved)) {
                        res.then(resolve, reject);
                    }
                } else if (isPromise(res.component)) {
                    res.component.then(resolve, reject);

                    if (isDef(res.error)) {
                        factory.errorComp = ensureCtor(res.error, baseCtor);
                    }

                    if (isDef(res.loading)) {
                        factory.loadingComp = ensureCtor(res.loading, baseCtor);
                        if (res.delay === 0) {
                            factory.loading = true;
                        } else {
                            timerLoading = setTimeout(function () {
                                timerLoading = null;
                                if (isUndef(factory.resolved) && isUndef(factory.error)) {
                                    factory.loading = true;
                                    forceRender(false);
                                }
                            }, res.delay || 200);
                        }
                    }

                    if (isDef(res.timeout)) {
                        timerTimeout = setTimeout(function () {
                            timerTimeout = null;
                            if (isUndef(factory.resolved)) {
                                reject(
                                    "timeout (" + (res.timeout) + "ms)"
                                );
                            }
                        }, res.timeout);
                    }
                }
            }

            sync = false;
            // return in case resolved synchronously
            return factory.loading
                ? factory.loadingComp
                : factory.resolved
        }
    }

    /*  */

    function isAsyncPlaceholder (node) {
        return node.isComment && node.asyncFactory
    }

    /*  */

    function getFirstComponentChild (children) {
        if (Array.isArray(children)) {
            for (var i = 0; i < children.length; i++) {
                var c = children[i];
                if (isDef(c) && (isDef(c.componentOptions) || isAsyncPlaceholder(c))) {
                    return c
                }
            }
        }
    }

    /*  */

    /*  */

    function initEvents (vm) {
        vm._events = Object.create(null);
        vm._hasHookEvent = false;
        // init parent attached events
        var listeners = vm.$options._parentListeners;
        if (listeners) {
            updateComponentListeners(vm, listeners);
        }
    }

    var target;

    function add (event, fn) {
        target.$on(event, fn);
    }

    function remove$1 (event, fn) {
        target.$off(event, fn);
    }

    function createOnceHandler (event, fn) {
        var _target = target;
        return function onceHandler () {
            var res = fn.apply(null, arguments);
            if (res !== null) {
                _target.$off(event, onceHandler);
            }
        }
    }

    function updateComponentListeners (
        vm,
        listeners,
        oldListeners
    ) {
        target = vm;
        updateListeners(listeners, oldListeners || {}, add, remove$1, createOnceHandler, vm);
        target = undefined;
    }

    function eventsMixin (Vue) {
        var hookRE = /^hook:/;
        Vue.prototype.$on = function (event, fn) {
            var vm = this;
            if (Array.isArray(event)) {
                for (var i = 0, l = event.length; i < l; i++) {
                    vm.$on(event[i], fn);
                }
            } else {
                (vm._events[event] || (vm._events[event] = [])).push(fn);
                // optimize hook:event cost by using a boolean flag marked at registration
                // instead of a hash lookup
                if (hookRE.test(event)) {
                    vm._hasHookEvent = true;
                }
            }
            return vm
        };

        Vue.prototype.$once = function (event, fn) {
            var vm = this;
            function on () {
                vm.$off(event, on);
                fn.apply(vm, arguments);
            }
            on.fn = fn;
            vm.$on(event, on);
            return vm
        };

        Vue.prototype.$off = function (event, fn) {
            var vm = this;
            // all
            if (!arguments.length) {
                vm._events = Object.create(null);
                return vm
            }
            // array of events
            if (Array.isArray(event)) {
                for (var i$1 = 0, l = event.length; i$1 < l; i$1++) {
                    vm.$off(event[i$1], fn);
                }
                return vm
            }
            // specific event
            var cbs = vm._events[event];
            if (!cbs) {
                return vm
            }
            if (!fn) {
                vm._events[event] = null;
                return vm
            }
            // specific handler
            var cb;
            var i = cbs.length;
            while (i--) {
                cb = cbs[i];
                if (cb === fn || cb.fn === fn) {
                    cbs.splice(i, 1);
                    break
                }
            }
            return vm
        };

        Vue.prototype.$emit = function (event) {
            var vm = this;
            {
                var lowerCaseEvent = event.toLowerCase();
                if (lowerCaseEvent !== event && vm._events[lowerCaseEvent]) {
                    tip(
                        "Event \"" + lowerCaseEvent + "\" is emitted in component " +
                        (formatComponentName(vm)) + " but the handler is registered for \"" + event + "\". " +
                        "Note that HTML attributes are case-insensitive and you cannot use " +
                        "v-on to listen to camelCase events when using in-DOM templates. " +
                        "You should probably use \"" + (hyphenate(event)) + "\" instead of \"" + event + "\"."
                    );
                }
            }
            var cbs = vm._events[event];
            if (cbs) {
                cbs = cbs.length > 1 ? toArray(cbs) : cbs;
                var args = toArray(arguments, 1);
                var info = "event handler for \"" + event + "\"";
                for (var i = 0, l = cbs.length; i < l; i++) {
                    invokeWithErrorHandling(cbs[i], vm, args, vm, info);
                }
            }
            return vm
        };
    }

    /*  */

    var activeInstance = null;
    var isUpdatingChildComponent = false;

    function setActiveInstance(vm) {
        var prevActiveInstance = activeInstance;
        activeInstance = vm;
        return function () {
            activeInstance = prevActiveInstance;
        }
    }

    function initLifecycle (vm) {
        var options = vm.$options;

        // locate first non-abstract parent
        var parent = options.parent;
        if (parent && !options.abstract) {
            while (parent.$options.abstract && parent.$parent) {
                parent = parent.$parent;
            }
            parent.$children.push(vm);
        }

        vm.$parent = parent;
        vm.$root = parent ? parent.$root : vm;

        vm.$children = [];
        vm.$refs = {};

        vm._watcher = null;
        vm._inactive = null;
        vm._directInactive = false;
        vm._isMounted = false;
        vm._isDestroyed = false;
        vm._isBeingDestroyed = false;
    }

    function lifecycleMixin (Vue) {
        Vue.prototype._update = function (vnode, hydrating) {
            var vm = this;
            var prevEl = vm.$el;
            var prevVnode = vm._vnode;
            var restoreActiveInstance = setActiveInstance(vm);
            vm._vnode = vnode;
            // Vue.prototype.__patch__ is injected in entry points
            // based on the rendering backend used.
            if (!prevVnode) {
                // initial render
                vm.$el = vm.__patch__(vm.$el, vnode, hydrating, false /* removeOnly */);
            } else {
                // updates
                vm.$el = vm.__patch__(prevVnode, vnode);
            }
            restoreActiveInstance();
            // update __vue__ reference
            if (prevEl) {
                prevEl.__vue__ = null;
            }
            if (vm.$el) {
                vm.$el.__vue__ = vm;
            }
            // if parent is an HOC, update its $el as well
            if (vm.$vnode && vm.$parent && vm.$vnode === vm.$parent._vnode) {
                vm.$parent.$el = vm.$el;
            }
            // updated hook is called by the scheduler to ensure that children are
            // updated in a parent's updated hook.
        };

        Vue.prototype.$forceUpdate = function () {
            var vm = this;
            if (vm._watcher) {
                vm._watcher.update();
            }
        };

        Vue.prototype.$destroy = function () {
            var vm = this;
            if (vm._isBeingDestroyed) {
                return
            }
            callHook(vm, 'beforeDestroy');
            vm._isBeingDestroyed = true;
            // remove self from parent
            var parent = vm.$parent;
            if (parent && !parent._isBeingDestroyed && !vm.$options.abstract) {
                remove(parent.$children, vm);
            }
            // teardown watchers
            if (vm._watcher) {
                vm._watcher.teardown();
            }
            var i = vm._watchers.length;
            while (i--) {
                vm._watchers[i].teardown();
            }
            // remove reference from data ob
            // frozen object may not have observer.
            if (vm._data.__ob__) {
                vm._data.__ob__.vmCount--;
            }
            // call the last hook...
            vm._isDestroyed = true;
            // invoke destroy hooks on current rendered tree
            vm.__patch__(vm._vnode, null);
            // fire destroyed hook
            callHook(vm, 'destroyed');
            // turn off all instance listeners.
            vm.$off();
            // remove __vue__ reference
            if (vm.$el) {
                vm.$el.__vue__ = null;
            }
            // release circular reference (#6759)
            if (vm.$vnode) {
                vm.$vnode.parent = null;
            }
        };
    }

    function mountComponent (
        vm,
        el,
        hydrating
    ) {
        vm.$el = el;
        if (!vm.$options.render) {
            vm.$options.render = createEmptyVNode;
            {
                /* istanbul ignore if */
                if ((vm.$options.template && vm.$options.template.charAt(0) !== '#') ||
                    vm.$options.el || el) {
                    warn(
                        'You are using the runtime-only build of Vue where the template ' +
                        'compiler is not available. Either pre-compile the templates into ' +
                        'render functions, or use the compiler-included build.',
                        vm
                    );
                } else {
                    warn(
                        'Failed to mount component: template or render function not defined.',
                        vm
                    );
                }
            }
        }
        callHook(vm, 'beforeMount');

        var updateComponent;
        /* istanbul ignore if */
        if (config.performance && mark) {
            updateComponent = function () {
                var name = vm._name;
                var id = vm._uid;
                var startTag = "vue-perf-start:" + id;
                var endTag = "vue-perf-end:" + id;

                mark(startTag);
                var vnode = vm._render();
                mark(endTag);
                measure(("vue " + name + " render"), startTag, endTag);

                mark(startTag);
                vm._update(vnode, hydrating);
                mark(endTag);
                measure(("vue " + name + " patch"), startTag, endTag);
            };
        } else {
            updateComponent = function () {
                vm._update(vm._render(), hydrating);
            };
        }

        // we set this to vm._watcher inside the watcher's constructor
        // since the watcher's initial patch may call $forceUpdate (e.g. inside child
        // component's mounted hook), which relies on vm._watcher being already defined
        new Watcher(vm, updateComponent, noop, {
            before: function before () {
                if (vm._isMounted && !vm._isDestroyed) {
                    callHook(vm, 'beforeUpdate');
                }
            }
        }, true /* isRenderWatcher */);
        hydrating = false;

        // manually mounted instance, call mounted on self
        // mounted is called for render-created child components in its inserted hook
        if (vm.$vnode == null) {
            vm._isMounted = true;
            callHook(vm, 'mounted');
        }
        return vm
    }

    function updateChildComponent (
        vm,
        propsData,
        listeners,
        parentVnode,
        renderChildren
    ) {
        {
            isUpdatingChildComponent = true;
        }

        // determine whether component has slot children
        // we need to do this before overwriting $options._renderChildren.

        // check if there are dynamic scopedSlots (hand-written or compiled but with
        // dynamic slot names). Static scoped slots compiled from template has the
        // "$stable" marker.
        var newScopedSlots = parentVnode.data.scopedSlots;
        var oldScopedSlots = vm.$scopedSlots;
        var hasDynamicScopedSlot = !!(
            (newScopedSlots && !newScopedSlots.$stable) ||
            (oldScopedSlots !== emptyObject && !oldScopedSlots.$stable) ||
            (newScopedSlots && vm.$scopedSlots.$key !== newScopedSlots.$key)
        );

        // Any static slot children from the parent may have changed during parent's
        // update. Dynamic scoped slots may also have changed. In such cases, a forced
        // update is necessary to ensure correctness.
        var needsForceUpdate = !!(
            renderChildren ||               // has new static slots
            vm.$options._renderChildren ||  // has old static slots
            hasDynamicScopedSlot
        );

        vm.$options._parentVnode = parentVnode;
        vm.$vnode = parentVnode; // update vm's placeholder node without re-render

        if (vm._vnode) { // update child tree's parent
            vm._vnode.parent = parentVnode;
        }
        vm.$options._renderChildren = renderChildren;

        // update $attrs and $listeners hash
        // these are also reactive so they may trigger child update if the child
        // used them during render
        vm.$attrs = parentVnode.data.attrs || emptyObject;
        vm.$listeners = listeners || emptyObject;

        // update props
        if (propsData && vm.$options.props) {
            toggleObserving(false);
            var props = vm._props;
            var propKeys = vm.$options._propKeys || [];
            for (var i = 0; i < propKeys.length; i++) {
                var key = propKeys[i];
                var propOptions = vm.$options.props; // wtf flow?
                props[key] = validateProp(key, propOptions, propsData, vm);
            }
            toggleObserving(true);
            // keep a copy of raw propsData
            vm.$options.propsData = propsData;
        }

        // update listeners
        listeners = listeners || emptyObject;
        var oldListeners = vm.$options._parentListeners;
        vm.$options._parentListeners = listeners;
        updateComponentListeners(vm, listeners, oldListeners);

        // resolve slots + force update if has children
        if (needsForceUpdate) {
            vm.$slots = resolveSlots(renderChildren, parentVnode.context);
            vm.$forceUpdate();
        }

        {
            isUpdatingChildComponent = false;
        }
    }

    function isInInactiveTree (vm) {
        while (vm && (vm = vm.$parent)) {
            if (vm._inactive) { return true }
        }
        return false
    }

    function activateChildComponent (vm, direct) {
        if (direct) {
            vm._directInactive = false;
            if (isInInactiveTree(vm)) {
                return
            }
        } else if (vm._directInactive) {
            return
        }
        if (vm._inactive || vm._inactive === null) {
            vm._inactive = false;
            for (var i = 0; i < vm.$children.length; i++) {
                activateChildComponent(vm.$children[i]);
            }
            callHook(vm, 'activated');
        }
    }

    function deactivateChildComponent (vm, direct) {
        if (direct) {
            vm._directInactive = true;
            if (isInInactiveTree(vm)) {
                return
            }
        }
        if (!vm._inactive) {
            vm._inactive = true;
            for (var i = 0; i < vm.$children.length; i++) {
                deactivateChildComponent(vm.$children[i]);
            }
            callHook(vm, 'deactivated');
        }
    }

    function callHook (vm, hook) {
        // #7573 disable dep collection when invoking lifecycle hooks
        pushTarget();
        var handlers = vm.$options[hook];
        var info = hook + " hook";
        if (handlers) {
            for (var i = 0, j = handlers.length; i < j; i++) {
                invokeWithErrorHandling(handlers[i], vm, null, vm, info);
            }
        }
        if (vm._hasHookEvent) {
            vm.$emit('hook:' + hook);
        }
        popTarget();
    }

    /*  */

    var MAX_UPDATE_COUNT = 100;

    var queue = [];
    var activatedChildren = [];
    var has = {};
    var circular = {};
    var waiting = false;
    var flushing = false;
    var index = 0;

    /**
     * Reset the scheduler's state.
     */
    function resetSchedulerState () {
        index = queue.length = activatedChildren.length = 0;
        has = {};
        {
            circular = {};
        }
        waiting = flushing = false;
    }

    // Async edge case #6566 requires saving the timestamp when event listeners are
    // attached. However, calling performance.now() has a perf overhead especially
    // if the page has thousands of event listeners. Instead, we take a timestamp
    // every time the scheduler flushes and use that for all event listeners
    // attached during that flush.
    var currentFlushTimestamp = 0;

    // Async edge case fix requires storing an event listener's attach timestamp.
    var getNow = Date.now;

    // Determine what event timestamp the browser is using. Annoyingly, the
    // timestamp can either be hi-res (relative to page load) or low-res
    // (relative to UNIX epoch), so in order to compare time we have to use the
    // same timestamp type when saving the flush timestamp.
    // All IE versions use low-res event timestamps, and have problematic clock
    // implementations (#9632)
    if (inBrowser && !isIE) {
        var performance = window.performance;
        if (
            performance &&
            typeof performance.now === 'function' &&
            getNow() > document.createEvent('Event').timeStamp
        ) {
            // if the event timestamp, although evaluated AFTER the Date.now(), is
            // smaller than it, it means the event is using a hi-res timestamp,
            // and we need to use the hi-res version for event listener timestamps as
            // well.
            getNow = function () { return performance.now(); };
        }
    }

    /**
     * Flush both queues and run the watchers.
     */
    function flushSchedulerQueue () {
        currentFlushTimestamp = getNow();
        flushing = true;
        var watcher, id;

        // Sort queue before flush.
        // This ensures that:
        // 1. Components are updated from parent to child. (because parent is always
        //    created before the child)
        // 2. A component's user watchers are run before its render watcher (because
        //    user watchers are created before the render watcher)
        // 3. If a component is destroyed during a parent component's watcher run,
        //    its watchers can be skipped.
        queue.sort(function (a, b) { return a.id - b.id; });

        // do not cache length because more watchers might be pushed
        // as we run existing watchers
        for (index = 0; index < queue.length; index++) {
            watcher = queue[index];
            if (watcher.before) {
                watcher.before();
            }
            id = watcher.id;
            has[id] = null;
            watcher.run();
            // in dev build, check and stop circular updates.
            if (has[id] != null) {
                circular[id] = (circular[id] || 0) + 1;
                if (circular[id] > MAX_UPDATE_COUNT) {
                    warn(
                        'You may have an infinite update loop ' + (
                            watcher.user
                                ? ("in watcher with expression \"" + (watcher.expression) + "\"")
                                : "in a component render function."
                        ),
                        watcher.vm
                    );
                    break
                }
            }
        }

        // keep copies of post queues before resetting state
        var activatedQueue = activatedChildren.slice();
        var updatedQueue = queue.slice();

        resetSchedulerState();

        // call component updated and activated hooks
        callActivatedHooks(activatedQueue);
        callUpdatedHooks(updatedQueue);

        // devtool hook
        /* istanbul ignore if */
        if (devtools && config.devtools) {
            devtools.emit('flush');
        }
    }

    function callUpdatedHooks (queue) {
        var i = queue.length;
        while (i--) {
            var watcher = queue[i];
            var vm = watcher.vm;
            if (vm._watcher === watcher && vm._isMounted && !vm._isDestroyed) {
                callHook(vm, 'updated');
            }
        }
    }

    /**
     * Queue a kept-alive component that was activated during patch.
     * The queue will be processed after the entire tree has been patched.
     */
    function queueActivatedComponent (vm) {
        // setting _inactive to false here so that a render function can
        // rely on checking whether it's in an inactive tree (e.g. router-view)
        vm._inactive = false;
        activatedChildren.push(vm);
    }

    function callActivatedHooks (queue) {
        for (var i = 0; i < queue.length; i++) {
            queue[i]._inactive = true;
            activateChildComponent(queue[i], true /* true */);
        }
    }

    /**
     * Push a watcher into the watcher queue.
     * Jobs with duplicate IDs will be skipped unless it's
     * pushed when the queue is being flushed.
     */
    function queueWatcher (watcher) {
        var id = watcher.id;
        if (has[id] == null) {
            has[id] = true;
            if (!flushing) {
                queue.push(watcher);
            } else {
                // if already flushing, splice the watcher based on its id
                // if already past its id, it will be run next immediately.
                var i = queue.length - 1;
                while (i > index && queue[i].id > watcher.id) {
                    i--;
                }
                queue.splice(i + 1, 0, watcher);
            }
            // queue the flush
            if (!waiting) {
                waiting = true;

                if (!config.async) {
                    flushSchedulerQueue();
                    return
                }
                nextTick(flushSchedulerQueue);
            }
        }
    }

    /*  */



    var uid$2 = 0;

    /**
     * A watcher parses an expression, collects dependencies,
     * and fires callback when the expression value changes.
     * This is used for both the $watch() api and directives.
     */
    var Watcher = function Watcher (
        vm,
        expOrFn,
        cb,
        options,
        isRenderWatcher
    ) {
        this.vm = vm;
        if (isRenderWatcher) {
            vm._watcher = this;
        }
        vm._watchers.push(this);
        // options
        if (options) {
            this.deep = !!options.deep;
            this.user = !!options.user;
            this.lazy = !!options.lazy;
            this.sync = !!options.sync;
            this.before = options.before;
        } else {
            this.deep = this.user = this.lazy = this.sync = false;
        }
        this.cb = cb;
        this.id = ++uid$2; // uid for batching
        this.active = true;
        this.dirty = this.lazy; // for lazy watchers
        this.deps = [];
        this.newDeps = [];
        this.depIds = new _Set();
        this.newDepIds = new _Set();
        this.expression = expOrFn.toString();
        // parse expression for getter
        if (typeof expOrFn === 'function') {
            this.getter = expOrFn;
        } else {
            this.getter = parsePath(expOrFn);
            if (!this.getter) {
                this.getter = noop;
                warn(
                    "Failed watching path: \"" + expOrFn + "\" " +
                    'Watcher only accepts simple dot-delimited paths. ' +
                    'For full control, use a function instead.',
                    vm
                );
            }
        }
        this.value = this.lazy
            ? undefined
            : this.get();
    };

    /**
     * Evaluate the getter, and re-collect dependencies.
     */
    Watcher.prototype.get = function get () {
        pushTarget(this);
        var value;
        var vm = this.vm;
        try {
            value = this.getter.call(vm, vm);
        } catch (e) {
            if (this.user) {
                handleError(e, vm, ("getter for watcher \"" + (this.expression) + "\""));
            } else {
                throw e
            }
        } finally {
            // "touch" every property so they are all tracked as
            // dependencies for deep watching
            if (this.deep) {
                traverse(value);
            }
            popTarget();
            this.cleanupDeps();
        }
        return value
    };

    /**
     * Add a dependency to this directive.
     */
    Watcher.prototype.addDep = function addDep (dep) {
        var id = dep.id;
        if (!this.newDepIds.has(id)) {
            this.newDepIds.add(id);
            this.newDeps.push(dep);
            if (!this.depIds.has(id)) {
                dep.addSub(this);
            }
        }
    };

    /**
     * Clean up for dependency collection.
     */
    Watcher.prototype.cleanupDeps = function cleanupDeps () {
        var i = this.deps.length;
        while (i--) {
            var dep = this.deps[i];
            if (!this.newDepIds.has(dep.id)) {
                dep.removeSub(this);
            }
        }
        var tmp = this.depIds;
        this.depIds = this.newDepIds;
        this.newDepIds = tmp;
        this.newDepIds.clear();
        tmp = this.deps;
        this.deps = this.newDeps;
        this.newDeps = tmp;
        this.newDeps.length = 0;
    };

    /**
     * Subscriber interface.
     * Will be called when a dependency changes.
     */
    Watcher.prototype.update = function update () {
        /* istanbul ignore else */
        if (this.lazy) {
            this.dirty = true;
        } else if (this.sync) {
            this.run();
        } else {
            queueWatcher(this);
        }
    };

    /**
     * Scheduler job interface.
     * Will be called by the scheduler.
     */
    Watcher.prototype.run = function run () {
        if (this.active) {
            var value = this.get();
            if (
                value !== this.value ||
                    // Deep watchers and watchers on Object/Arrays should fire even
                    // when the value is the same, because the value may
                    // have mutated.
                isObject(value) ||
                this.deep
            ) {
                // set new value
                var oldValue = this.value;
                this.value = value;
                if (this.user) {
                    try {
                        this.cb.call(this.vm, value, oldValue);
                    } catch (e) {
                        handleError(e, this.vm, ("callback for watcher \"" + (this.expression) + "\""));
                    }
                } else {
                    this.cb.call(this.vm, value, oldValue);
                }
            }
        }
    };

    /**
     * Evaluate the value of the watcher.
     * This only gets called for lazy watchers.
     */
    Watcher.prototype.evaluate = function evaluate () {
        this.value = this.get();
        this.dirty = false;
    };

    /**
     * Depend on all deps collected by this watcher.
     */
    Watcher.prototype.depend = function depend () {
        var i = this.deps.length;
        while (i--) {
            this.deps[i].depend();
        }
    };

    /**
     * Remove self from all dependencies' subscriber list.
     */
    Watcher.prototype.teardown = function teardown () {
        if (this.active) {
            // remove self from vm's watcher list
            // this is a somewhat expensive operation so we skip it
            // if the vm is being destroyed.
            if (!this.vm._isBeingDestroyed) {
                remove(this.vm._watchers, this);
            }
            var i = this.deps.length;
            while (i--) {
                this.deps[i].removeSub(this);
            }
            this.active = false;
        }
    };

    /*  */

    var sharedPropertyDefinition = {
        enumerable: true,
        configurable: true,
        get: noop,
        set: noop
    };

    function proxy (target, sourceKey, key) {
        sharedPropertyDefinition.get = function proxyGetter () {
            return this[sourceKey][key]
        };
        sharedPropertyDefinition.set = function proxySetter (val) {
            this[sourceKey][key] = val;
        };
        Object.defineProperty(target, key, sharedPropertyDefinition);
    }

    function initState (vm) {
        vm._watchers = [];
        var opts = vm.$options;
        if (opts.props) { initProps(vm, opts.props); }
        if (opts.methods) { initMethods(vm, opts.methods); }
        if (opts.data) {
            initData(vm);
        } else {
            observe(vm._data = {}, true /* asRootData */);
        }
        if (opts.computed) { initComputed(vm, opts.computed); }
        if (opts.watch && opts.watch !== nativeWatch) {
            initWatch(vm, opts.watch);
        }
    }

    function initProps (vm, propsOptions) {
        var propsData = vm.$options.propsData || {};
        var props = vm._props = {};
        // cache prop keys so that future props updates can iterate using Array
        // instead of dynamic object key enumeration.
        var keys = vm.$options._propKeys = [];
        var isRoot = !vm.$parent;
        // root instance props should be converted
        if (!isRoot) {
            toggleObserving(false);
        }
        var loop = function ( key ) {
            keys.push(key);
            var value = validateProp(key, propsOptions, propsData, vm);
            /* istanbul ignore else */
            {
                var hyphenatedKey = hyphenate(key);
                if (isReservedAttribute(hyphenatedKey) ||
                    config.isReservedAttr(hyphenatedKey)) {
                    warn(
                        ("\"" + hyphenatedKey + "\" is a reserved attribute and cannot be used as component prop."),
                        vm
                    );
                }
                defineReactive$$1(props, key, value, function () {
                    if (!isRoot && !isUpdatingChildComponent) {
                        warn(
                            "Avoid mutating a prop directly since the value will be " +
                            "overwritten whenever the parent component re-renders. " +
                            "Instead, use a data or computed property based on the prop's " +
                            "value. Prop being mutated: \"" + key + "\"",
                            vm
                        );
                    }
                });
            }
            // static props are already proxied on the component's prototype
            // during Vue.extend(). We only need to proxy props defined at
            // instantiation here.
            if (!(key in vm)) {
                proxy(vm, "_props", key);
            }
        };

        for (var key in propsOptions) loop( key );
        toggleObserving(true);
    }

    function initData (vm) {
        var data = vm.$options.data;
        data = vm._data = typeof data === 'function'
            ? getData(data, vm)
            : data || {};
        if (!isPlainObject(data)) {
            data = {};
            warn(
                'data functions should return an object:\n' +
                'https://vuejs.org/v2/guide/components.html#data-Must-Be-a-Function',
                vm
            );
        }
        // proxy data on instance
        var keys = Object.keys(data);
        var props = vm.$options.props;
        var methods = vm.$options.methods;
        var i = keys.length;
        while (i--) {
            var key = keys[i];
            {
                if (methods && hasOwn(methods, key)) {
                    warn(
                        ("Method \"" + key + "\" has already been defined as a data property."),
                        vm
                    );
                }
            }
            if (props && hasOwn(props, key)) {
                warn(
                    "The data property \"" + key + "\" is already declared as a prop. " +
                    "Use prop default value instead.",
                    vm
                );
            } else if (!isReserved(key)) {
                proxy(vm, "_data", key);
            }
        }
        // observe data
        observe(data, true /* asRootData */);
    }

    function getData (data, vm) {
        // #7573 disable dep collection when invoking data getters
        pushTarget();
        try {
            return data.call(vm, vm)
        } catch (e) {
            handleError(e, vm, "data()");
            return {}
        } finally {
            popTarget();
        }
    }

    var computedWatcherOptions = { lazy: true };

    function initComputed (vm, computed) {
        // $flow-disable-line
        var watchers = vm._computedWatchers = Object.create(null);
        // computed properties are just getters during SSR
        var isSSR = isServerRendering();

        for (var key in computed) {
            var userDef = computed[key];
            var getter = typeof userDef === 'function' ? userDef : userDef.get;
            if (getter == null) {
                warn(
                    ("Getter is missing for computed property \"" + key + "\"."),
                    vm
                );
            }

            if (!isSSR) {
                // create internal watcher for the computed property.
                watchers[key] = new Watcher(
                    vm,
                    getter || noop,
                    noop,
                    computedWatcherOptions
                );
            }

            // component-defined computed properties are already defined on the
            // component prototype. We only need to define computed properties defined
            // at instantiation here.
            if (!(key in vm)) {
                defineComputed(vm, key, userDef);
            } else {
                if (key in vm.$data) {
                    warn(("The computed property \"" + key + "\" is already defined in data."), vm);
                } else if (vm.$options.props && key in vm.$options.props) {
                    warn(("The computed property \"" + key + "\" is already defined as a prop."), vm);
                }
            }
        }
    }

    function defineComputed (
        target,
        key,
        userDef
    ) {
        var shouldCache = !isServerRendering();
        if (typeof userDef === 'function') {
            sharedPropertyDefinition.get = shouldCache
                ? createComputedGetter(key)
                : createGetterInvoker(userDef);
            sharedPropertyDefinition.set = noop;
        } else {
            sharedPropertyDefinition.get = userDef.get
                ? shouldCache && userDef.cache !== false
                ? createComputedGetter(key)
                : createGetterInvoker(userDef.get)
                : noop;
            sharedPropertyDefinition.set = userDef.set || noop;
        }
        if (sharedPropertyDefinition.set === noop) {
            sharedPropertyDefinition.set = function () {
                warn(
                    ("Computed property \"" + key + "\" was assigned to but it has no setter."),
                    this
                );
            };
        }
        Object.defineProperty(target, key, sharedPropertyDefinition);
    }

    function createComputedGetter (key) {
        return function computedGetter () {
            var watcher = this._computedWatchers && this._computedWatchers[key];
            if (watcher) {
                if (watcher.dirty) {
                    watcher.evaluate();
                }
                if (Dep.target) {
                    watcher.depend();
                }
                return watcher.value
            }
        }
    }

    function createGetterInvoker(fn) {
        return function computedGetter () {
            return fn.call(this, this)
        }
    }

    function initMethods (vm, methods) {
        var props = vm.$options.props;
        for (var key in methods) {
            {
                if (typeof methods[key] !== 'function') {
                    warn(
                        "Method \"" + key + "\" has type \"" + (typeof methods[key]) + "\" in the component definition. " +
                        "Did you reference the function correctly?",
                        vm
                    );
                }
                if (props && hasOwn(props, key)) {
                    warn(
                        ("Method \"" + key + "\" has already been defined as a prop."),
                        vm
                    );
                }
                if ((key in vm) && isReserved(key)) {
                    warn(
                        "Method \"" + key + "\" conflicts with an existing Vue instance method. " +
                        "Avoid defining component methods that start with _ or $."
                    );
                }
            }
            vm[key] = typeof methods[key] !== 'function' ? noop : bind(methods[key], vm);
        }
    }

    function initWatch (vm, watch) {
        for (var key in watch) {
            var handler = watch[key];
            if (Array.isArray(handler)) {
                for (var i = 0; i < handler.length; i++) {
                    createWatcher(vm, key, handler[i]);
                }
            } else {
                createWatcher(vm, key, handler);
            }
        }
    }

    function createWatcher (
        vm,
        expOrFn,
        handler,
        options
    ) {
        if (isPlainObject(handler)) {
            options = handler;
            handler = handler.handler;
        }
        if (typeof handler === 'string') {
            handler = vm[handler];
        }
        return vm.$watch(expOrFn, handler, options)
    }

    function stateMixin (Vue) {
        // flow somehow has problems with directly declared definition object
        // when using Object.defineProperty, so we have to procedurally build up
        // the object here.
        var dataDef = {};
        dataDef.get = function () { return this._data };
        var propsDef = {};
        propsDef.get = function () { return this._props };
        {
            dataDef.set = function () {
                warn(
                    'Avoid replacing instance root $data. ' +
                    'Use nested data properties instead.',
                    this
                );
            };
            propsDef.set = function () {
                warn("$props is readonly.", this);
            };
        }
        Object.defineProperty(Vue.prototype, '$data', dataDef);
        Object.defineProperty(Vue.prototype, '$props', propsDef);

        Vue.prototype.$set = set;
        Vue.prototype.$delete = del;

        Vue.prototype.$watch = function (
            expOrFn,
            cb,
            options
        ) {
            var vm = this;
            if (isPlainObject(cb)) {
                return createWatcher(vm, expOrFn, cb, options)
            }
            options = options || {};
            options.user = true;
            var watcher = new Watcher(vm, expOrFn, cb, options);
            if (options.immediate) {
                try {
                    cb.call(vm, watcher.value);
                } catch (error) {
                    handleError(error, vm, ("callback for immediate watcher \"" + (watcher.expression) + "\""));
                }
            }
            return function unwatchFn () {
                watcher.teardown();
            }
        };
    }

    /*  */

    var uid$3 = 0;

    function initMixin (Vue) {
        Vue.prototype._init = function (options) {
            var vm = this;
            // a uid
            vm._uid = uid$3++;

            var startTag, endTag;
            /* istanbul ignore if */
            if (config.performance && mark) {
                startTag = "vue-perf-start:" + (vm._uid);
                endTag = "vue-perf-end:" + (vm._uid);
                mark(startTag);
            }

            // a flag to avoid this being observed
            vm._isVue = true;
            // merge options
            if (options && options._isComponent) {
                // optimize internal component instantiation
                // since dynamic options merging is pretty slow, and none of the
                // internal component options needs special treatment.
                initInternalComponent(vm, options);
            } else {
                vm.$options = mergeOptions(
                    resolveConstructorOptions(vm.constructor),
                    options || {},
                    vm
                );
            }
            /* istanbul ignore else */
            {
                initProxy(vm);
            }
            // expose real self
            vm._self = vm;
            initLifecycle(vm);
            initEvents(vm);
            initRender(vm);
            callHook(vm, 'beforeCreate');
            initInjections(vm); // resolve injections before data/props
            initState(vm);
            initProvide(vm); // resolve provide after data/props
            callHook(vm, 'created');

            /* istanbul ignore if */
            if (config.performance && mark) {
                vm._name = formatComponentName(vm, false);
                mark(endTag);
                measure(("vue " + (vm._name) + " init"), startTag, endTag);
            }

            if (vm.$options.el) {
                vm.$mount(vm.$options.el);
            }
        };
    }

    function initInternalComponent (vm, options) {
        var opts = vm.$options = Object.create(vm.constructor.options);
        // doing this because it's faster than dynamic enumeration.
        var parentVnode = options._parentVnode;
        opts.parent = options.parent;
        opts._parentVnode = parentVnode;

        var vnodeComponentOptions = parentVnode.componentOptions;
        opts.propsData = vnodeComponentOptions.propsData;
        opts._parentListeners = vnodeComponentOptions.listeners;
        opts._renderChildren = vnodeComponentOptions.children;
        opts._componentTag = vnodeComponentOptions.tag;

        if (options.render) {
            opts.render = options.render;
            opts.staticRenderFns = options.staticRenderFns;
        }
    }

    function resolveConstructorOptions (Ctor) {
        var options = Ctor.options;
        if (Ctor.super) {
            var superOptions = resolveConstructorOptions(Ctor.super);
            var cachedSuperOptions = Ctor.superOptions;
            if (superOptions !== cachedSuperOptions) {
                // super option changed,
                // need to resolve new options.
                Ctor.superOptions = superOptions;
                // check if there are any late-modified/attached options (#4976)
                var modifiedOptions = resolveModifiedOptions(Ctor);
                // update base extend options
                if (modifiedOptions) {
                    extend(Ctor.extendOptions, modifiedOptions);
                }
                options = Ctor.options = mergeOptions(superOptions, Ctor.extendOptions);
                if (options.name) {
                    options.components[options.name] = Ctor;
                }
            }
        }
        return options
    }

    function resolveModifiedOptions (Ctor) {
        var modified;
        var latest = Ctor.options;
        var sealed = Ctor.sealedOptions;
        for (var key in latest) {
            if (latest[key] !== sealed[key]) {
                if (!modified) { modified = {}; }
                modified[key] = latest[key];
            }
        }
        return modified
    }

    function Vue (options) {
        if (!(this instanceof Vue)
        ) {
            warn('Vue is a constructor and should be called with the `new` keyword');
        }
        this._init(options);
    }

    initMixin(Vue);
    stateMixin(Vue);
    eventsMixin(Vue);
    lifecycleMixin(Vue);
    renderMixin(Vue);

    /*  */

    function initUse (Vue) {
        Vue.use = function (plugin) {
            var installedPlugins = (this._installedPlugins || (this._installedPlugins = []));
            if (installedPlugins.indexOf(plugin) > -1) {
                return this
            }

            // additional parameters
            var args = toArray(arguments, 1);
            args.unshift(this);
            if (typeof plugin.install === 'function') {
                plugin.install.apply(plugin, args);
            } else if (typeof plugin === 'function') {
                plugin.apply(null, args);
            }
            installedPlugins.push(plugin);
            return this
        };
    }

    /*  */

    function initMixin$1 (Vue) {
        Vue.mixin = function (mixin) {
            this.options = mergeOptions(this.options, mixin);
            return this
        };
    }

    /*  */

    function initExtend (Vue) {
        /**
         * Each instance constructor, including Vue, has a unique
         * cid. This enables us to create wrapped "child
         * constructors" for prototypal inheritance and cache them.
         */
        Vue.cid = 0;
        var cid = 1;

        /**
         * Class inheritance
         */
        Vue.extend = function (extendOptions) {
            extendOptions = extendOptions || {};
            var Super = this;
            var SuperId = Super.cid;
            var cachedCtors = extendOptions._Ctor || (extendOptions._Ctor = {});
            if (cachedCtors[SuperId]) {
                return cachedCtors[SuperId]
            }

            var name = extendOptions.name || Super.options.name;
            if (name) {
                validateComponentName(name);
            }

            var Sub = function VueComponent (options) {
                this._init(options);
            };
            Sub.prototype = Object.create(Super.prototype);
            Sub.prototype.constructor = Sub;
            Sub.cid = cid++;
            Sub.options = mergeOptions(
                Super.options,
                extendOptions
            );
            Sub['super'] = Super;

            // For props and computed properties, we define the proxy getters on
            // the Vue instances at extension time, on the extended prototype. This
            // avoids Object.defineProperty calls for each instance created.
            if (Sub.options.props) {
                initProps$1(Sub);
            }
            if (Sub.options.computed) {
                initComputed$1(Sub);
            }

            // allow further extension/mixin/plugin usage
            Sub.extend = Super.extend;
            Sub.mixin = Super.mixin;
            Sub.use = Super.use;

            // create asset registers, so extended classes
            // can have their private assets too.
            ASSET_TYPES.forEach(function (type) {
                Sub[type] = Super[type];
            });
            // enable recursive self-lookup
            if (name) {
                Sub.options.components[name] = Sub;
            }

            // keep a reference to the super options at extension time.
            // later at instantiation we can check if Super's options have
            // been updated.
            Sub.superOptions = Super.options;
            Sub.extendOptions = extendOptions;
            Sub.sealedOptions = extend({}, Sub.options);

            // cache constructor
            cachedCtors[SuperId] = Sub;
            return Sub
        };
    }

    function initProps$1 (Comp) {
        var props = Comp.options.props;
        for (var key in props) {
            proxy(Comp.prototype, "_props", key);
        }
    }

    function initComputed$1 (Comp) {
        var computed = Comp.options.computed;
        for (var key in computed) {
            defineComputed(Comp.prototype, key, computed[key]);
        }
    }

    /*  */

    function initAssetRegisters (Vue) {
        /**
         * Create asset registration methods.
         */
        ASSET_TYPES.forEach(function (type) {
            Vue[type] = function (
                id,
                definition
            ) {
                if (!definition) {
                    return this.options[type + 's'][id]
                } else {
                    /* istanbul ignore if */
                    if (type === 'component') {
                        validateComponentName(id);
                    }
                    if (type === 'component' && isPlainObject(definition)) {
                        definition.name = definition.name || id;
                        definition = this.options._base.extend(definition);
                    }
                    if (type === 'directive' && typeof definition === 'function') {
                        definition = { bind: definition, update: definition };
                    }
                    this.options[type + 's'][id] = definition;
                    return definition
                }
            };
        });
    }

    /*  */



    function getComponentName (opts) {
        return opts && (opts.Ctor.options.name || opts.tag)
    }

    function matches (pattern, name) {
        if (Array.isArray(pattern)) {
            return pattern.indexOf(name) > -1
        } else if (typeof pattern === 'string') {
            return pattern.split(',').indexOf(name) > -1
        } else if (isRegExp(pattern)) {
            return pattern.test(name)
        }
        /* istanbul ignore next */
        return false
    }

    function pruneCache (keepAliveInstance, filter) {
        var cache = keepAliveInstance.cache;
        var keys = keepAliveInstance.keys;
        var _vnode = keepAliveInstance._vnode;
        for (var key in cache) {
            var cachedNode = cache[key];
            if (cachedNode) {
                var name = getComponentName(cachedNode.componentOptions);
                if (name && !filter(name)) {
                    pruneCacheEntry(cache, key, keys, _vnode);
                }
            }
        }
    }

    function pruneCacheEntry (
        cache,
        key,
        keys,
        current
    ) {
        var cached$$1 = cache[key];
        if (cached$$1 && (!current || cached$$1.tag !== current.tag)) {
            cached$$1.componentInstance.$destroy();
        }
        cache[key] = null;
        remove(keys, key);
    }

    var patternTypes = [String, RegExp, Array];

    var KeepAlive = {
        name: 'keep-alive',
        abstract: true,

        props: {
            include: patternTypes,
            exclude: patternTypes,
            max: [String, Number]
        },

        created: function created () {
            this.cache = Object.create(null);
            this.keys = [];
        },

        destroyed: function destroyed () {
            for (var key in this.cache) {
                pruneCacheEntry(this.cache, key, this.keys);
            }
        },

        mounted: function mounted () {
            var this$1 = this;

            this.$watch('include', function (val) {
                pruneCache(this$1, function (name) { return matches(val, name); });
            });
            this.$watch('exclude', function (val) {
                pruneCache(this$1, function (name) { return !matches(val, name); });
            });
        },

        render: function render () {
            var slot = this.$slots.default;
            var vnode = getFirstComponentChild(slot);
            var componentOptions = vnode && vnode.componentOptions;
            if (componentOptions) {
                // check pattern
                var name = getComponentName(componentOptions);
                var ref = this;
                var include = ref.include;
                var exclude = ref.exclude;
                if (
                    // not included
                (include && (!name || !matches(include, name))) ||
                    // excluded
                (exclude && name && matches(exclude, name))
                ) {
                    return vnode
                }

                var ref$1 = this;
                var cache = ref$1.cache;
                var keys = ref$1.keys;
                var key = vnode.key == null
                    // same constructor may get registered as different local components
                    // so cid alone is not enough (#3269)
                    ? componentOptions.Ctor.cid + (componentOptions.tag ? ("::" + (componentOptions.tag)) : '')
                    : vnode.key;
                if (cache[key]) {
                    vnode.componentInstance = cache[key].componentInstance;
                    // make current key freshest
                    remove(keys, key);
                    keys.push(key);
                } else {
                    cache[key] = vnode;
                    keys.push(key);
                    // prune oldest entry
                    if (this.max && keys.length > parseInt(this.max)) {
                        pruneCacheEntry(cache, keys[0], keys, this._vnode);
                    }
                }

                vnode.data.keepAlive = true;
            }
            return vnode || (slot && slot[0])
        }
    };

    var builtInComponents = {
        KeepAlive: KeepAlive
    };

    /*  */

    function initGlobalAPI (Vue) {
        // config
        var configDef = {};
        configDef.get = function () { return config; };
        {
            configDef.set = function () {
                warn(
                    'Do not replace the Vue.config object, set individual fields instead.'
                );
            };
        }
        Object.defineProperty(Vue, 'config', configDef);

        // exposed util methods.
        // NOTE: these are not considered part of the public API - avoid relying on
        // them unless you are aware of the risk.
        Vue.util = {
            warn: warn,
            extend: extend,
            mergeOptions: mergeOptions,
            defineReactive: defineReactive$$1
        };

        Vue.set = set;
        Vue.delete = del;
        Vue.nextTick = nextTick;

        // 2.6 explicit observable API
        Vue.observable = function (obj) {
            observe(obj);
            return obj
        };

        Vue.options = Object.create(null);
        ASSET_TYPES.forEach(function (type) {
            Vue.options[type + 's'] = Object.create(null);
        });

        // this is used to identify the "base" constructor to extend all plain-object
        // components with in Weex's multi-instance scenarios.
        Vue.options._base = Vue;

        extend(Vue.options.components, builtInComponents);

        initUse(Vue);
        initMixin$1(Vue);
        initExtend(Vue);
        initAssetRegisters(Vue);
    }

    initGlobalAPI(Vue);

    Object.defineProperty(Vue.prototype, '$isServer', {
        get: isServerRendering
    });

    Object.defineProperty(Vue.prototype, '$ssrContext', {
        get: function get () {
            /* istanbul ignore next */
            return this.$vnode && this.$vnode.ssrContext
        }
    });

    // expose FunctionalRenderContext for ssr runtime helper installation
    Object.defineProperty(Vue, 'FunctionalRenderContext', {
        value: FunctionalRenderContext
    });

    Vue.version = '2.6.10';

    /*  */

    // these are reserved for web because they are directly compiled away
    // during template compilation
    var isReservedAttr = makeMap('style,class');

    // attributes that should be using props for binding
    var acceptValue = makeMap('input,textarea,option,select,progress');
    var mustUseProp = function (tag, type, attr) {
        return (
            (attr === 'value' && acceptValue(tag)) && type !== 'button' ||
            (attr === 'selected' && tag === 'option') ||
            (attr === 'checked' && tag === 'input') ||
            (attr === 'muted' && tag === 'video')
        )
    };

    var isEnumeratedAttr = makeMap('contenteditable,draggable,spellcheck');

    var isValidContentEditableValue = makeMap('events,caret,typing,plaintext-only');

    var convertEnumeratedValue = function (key, value) {
        return isFalsyAttrValue(value) || value === 'false'
            ? 'false'
            // allow arbitrary string value for contenteditable
            : key === 'contenteditable' && isValidContentEditableValue(value)
            ? value
            : 'true'
    };

    var isBooleanAttr = makeMap(
        'allowfullscreen,async,autofocus,autoplay,checked,compact,controls,declare,' +
        'default,defaultchecked,defaultmuted,defaultselected,defer,disabled,' +
        'enabled,formnovalidate,hidden,indeterminate,inert,ismap,itemscope,loop,multiple,' +
        'muted,nohref,noresize,noshade,novalidate,nowrap,open,pauseonexit,readonly,' +
        'required,reversed,scoped,seamless,selected,sortable,translate,' +
        'truespeed,typemustmatch,visible'
    );

    var xlinkNS = 'http://www.w3.org/1999/xlink';

    var isXlink = function (name) {
        return name.charAt(5) === ':' && name.slice(0, 5) === 'xlink'
    };

    var getXlinkProp = function (name) {
        return isXlink(name) ? name.slice(6, name.length) : ''
    };

    var isFalsyAttrValue = function (val) {
        return val == null || val === false
    };

    /*  */

    function genClassForVnode (vnode) {
        var data = vnode.data;
        var parentNode = vnode;
        var childNode = vnode;
        while (isDef(childNode.componentInstance)) {
            childNode = childNode.componentInstance._vnode;
            if (childNode && childNode.data) {
                data = mergeClassData(childNode.data, data);
            }
        }
        while (isDef(parentNode = parentNode.parent)) {
            if (parentNode && parentNode.data) {
                data = mergeClassData(data, parentNode.data);
            }
        }
        return renderClass(data.staticClass, data.class)
    }

    function mergeClassData (child, parent) {
        return {
            staticClass: concat(child.staticClass, parent.staticClass),
            class: isDef(child.class)
                ? [child.class, parent.class]
                : parent.class
        }
    }

    function renderClass (
        staticClass,
        dynamicClass
    ) {
        if (isDef(staticClass) || isDef(dynamicClass)) {
            return concat(staticClass, stringifyClass(dynamicClass))
        }
        /* istanbul ignore next */
        return ''
    }

    function concat (a, b) {
        return a ? b ? (a + ' ' + b) : a : (b || '')
    }

    function stringifyClass (value) {
        if (Array.isArray(value)) {
            return stringifyArray(value)
        }
        if (isObject(value)) {
            return stringifyObject(value)
        }
        if (typeof value === 'string') {
            return value
        }
        /* istanbul ignore next */
        return ''
    }

    function stringifyArray (value) {
        var res = '';
        var stringified;
        for (var i = 0, l = value.length; i < l; i++) {
            if (isDef(stringified = stringifyClass(value[i])) && stringified !== '') {
                if (res) { res += ' '; }
                res += stringified;
            }
        }
        return res
    }

    function stringifyObject (value) {
        var res = '';
        for (var key in value) {
            if (value[key]) {
                if (res) { res += ' '; }
                res += key;
            }
        }
        return res
    }

    /*  */

    var namespaceMap = {
        svg: 'http://www.w3.org/2000/svg',
        math: 'http://www.w3.org/1998/Math/MathML'
    };

    var isHTMLTag = makeMap(
        'html,body,base,head,link,meta,style,title,' +
        'address,article,aside,footer,header,h1,h2,h3,h4,h5,h6,hgroup,nav,section,' +
        'div,dd,dl,dt,figcaption,figure,picture,hr,img,li,main,ol,p,pre,ul,' +
        'a,b,abbr,bdi,bdo,br,cite,code,data,dfn,em,i,kbd,mark,q,rp,rt,rtc,ruby,' +
        's,samp,small,span,strong,sub,sup,time,u,var,wbr,area,audio,map,track,video,' +
        'embed,object,param,source,canvas,script,noscript,del,ins,' +
        'caption,col,colgroup,table,thead,tbody,td,th,tr,' +
        'button,datalist,fieldset,form,input,label,legend,meter,optgroup,option,' +
        'output,progress,select,textarea,' +
        'details,dialog,menu,menuitem,summary,' +
        'content,element,shadow,template,blockquote,iframe,tfoot'
    );

    // this map is intentionally selective, only covering SVG elements that may
    // contain child elements.
    var isSVG = makeMap(
        'svg,animate,circle,clippath,cursor,defs,desc,ellipse,filter,font-face,' +
        'foreignObject,g,glyph,image,line,marker,mask,missing-glyph,path,pattern,' +
        'polygon,polyline,rect,switch,symbol,text,textpath,tspan,use,view',
        true
    );

    var isPreTag = function (tag) { return tag === 'pre'; };

    var isReservedTag = function (tag) {
        return isHTMLTag(tag) || isSVG(tag)
    };

    function getTagNamespace (tag) {
        if (isSVG(tag)) {
            return 'svg'
        }
        // basic support for MathML
        // note it doesn't support other MathML elements being component roots
        if (tag === 'math') {
            return 'math'
        }
    }

    var unknownElementCache = Object.create(null);
    function isUnknownElement (tag) {
        /* istanbul ignore if */
        if (!inBrowser) {
            return true
        }
        if (isReservedTag(tag)) {
            return false
        }
        tag = tag.toLowerCase();
        /* istanbul ignore if */
        if (unknownElementCache[tag] != null) {
            return unknownElementCache[tag]
        }
        var el = document.createElement(tag);
        if (tag.indexOf('-') > -1) {
            // http://stackoverflow.com/a/28210364/1070244
            return (unknownElementCache[tag] = (
                el.constructor === window.HTMLUnknownElement ||
                el.constructor === window.HTMLElement
            ))
        } else {
            return (unknownElementCache[tag] = /HTMLUnknownElement/.test(el.toString()))
        }
    }

    var isTextInputType = makeMap('text,number,password,search,email,tel,url');

    /*  */

    /**
     * Query an element selector if it's not an element already.
     */
    function query (el) {
        if (typeof el === 'string') {
            var selected = document.querySelector(el);
            if (!selected) {
                warn(
                    'Cannot find element: ' + el
                );
                return document.createElement('div')
            }
            return selected
        } else {
            return el
        }
    }

    /*  */

    function createElement$1 (tagName, vnode) {
        var elm = document.createElement(tagName);
        if (tagName !== 'select') {
            return elm
        }
        // false or null will remove the attribute but undefined will not
        if (vnode.data && vnode.data.attrs && vnode.data.attrs.multiple !== undefined) {
            elm.setAttribute('multiple', 'multiple');
        }
        return elm
    }

    function createElementNS (namespace, tagName) {
        return document.createElementNS(namespaceMap[namespace], tagName)
    }

    function createTextNode (text) {
        return document.createTextNode(text)
    }

    function createComment (text) {
        return document.createComment(text)
    }

    function insertBefore (parentNode, newNode, referenceNode) {
        parentNode.insertBefore(newNode, referenceNode);
    }

    function removeChild (node, child) {
        node.removeChild(child);
    }

    function appendChild (node, child) {
        node.appendChild(child);
    }

    function parentNode (node) {
        return node.parentNode
    }

    function nextSibling (node) {
        return node.nextSibling
    }

    function tagName (node) {
        return node.tagName
    }

    function setTextContent (node, text) {
        node.textContent = text;
    }

    function setStyleScope (node, scopeId) {
        node.setAttribute(scopeId, '');
    }

    var nodeOps = /*#__PURE__*/Object.freeze({
        createElement: createElement$1,
        createElementNS: createElementNS,
        createTextNode: createTextNode,
        createComment: createComment,
        insertBefore: insertBefore,
        removeChild: removeChild,
        appendChild: appendChild,
        parentNode: parentNode,
        nextSibling: nextSibling,
        tagName: tagName,
        setTextContent: setTextContent,
        setStyleScope: setStyleScope
    });

    /*  */

    var ref = {
        create: function create (_, vnode) {
            registerRef(vnode);
        },
        update: function update (oldVnode, vnode) {
            if (oldVnode.data.ref !== vnode.data.ref) {
                registerRef(oldVnode, true);
                registerRef(vnode);
            }
        },
        destroy: function destroy (vnode) {
            registerRef(vnode, true);
        }
    };

    function registerRef (vnode, isRemoval) {
        var key = vnode.data.ref;
        if (!isDef(key)) { return }

        var vm = vnode.context;
        var ref = vnode.componentInstance || vnode.elm;
        var refs = vm.$refs;
        if (isRemoval) {
            if (Array.isArray(refs[key])) {
                remove(refs[key], ref);
            } else if (refs[key] === ref) {
                refs[key] = undefined;
            }
        } else {
            if (vnode.data.refInFor) {
                if (!Array.isArray(refs[key])) {
                    refs[key] = [ref];
                } else if (refs[key].indexOf(ref) < 0) {
                    // $flow-disable-line
                    refs[key].push(ref);
                }
            } else {
                refs[key] = ref;
            }
        }
    }

    /**
     * Virtual DOM patching algorithm based on Snabbdom by
     * Simon Friis Vindum (@paldepind)
     * Licensed under the MIT License
     * https://github.com/paldepind/snabbdom/blob/master/LICENSE
     *
     * modified by Evan You (@yyx990803)
     *
     * Not type-checking this because this file is perf-critical and the cost
     * of making flow understand it is not worth it.
     */

    var emptyNode = new VNode('', {}, []);

    var hooks = ['create', 'activate', 'update', 'remove', 'destroy'];

    function sameVnode (a, b) {
        return (
            a.key === b.key && (
                (
                    a.tag === b.tag &&
                    a.isComment === b.isComment &&
                    isDef(a.data) === isDef(b.data) &&
                    sameInputType(a, b)
                ) || (
                    isTrue(a.isAsyncPlaceholder) &&
                    a.asyncFactory === b.asyncFactory &&
                    isUndef(b.asyncFactory.error)
                )
            )
        )
    }

    function sameInputType (a, b) {
        if (a.tag !== 'input') { return true }
        var i;
        var typeA = isDef(i = a.data) && isDef(i = i.attrs) && i.type;
        var typeB = isDef(i = b.data) && isDef(i = i.attrs) && i.type;
        return typeA === typeB || isTextInputType(typeA) && isTextInputType(typeB)
    }

    function createKeyToOldIdx (children, beginIdx, endIdx) {
        var i, key;
        var map = {};
        for (i = beginIdx; i <= endIdx; ++i) {
            key = children[i].key;
            if (isDef(key)) { map[key] = i; }
        }
        return map
    }

    function createPatchFunction (backend) {
        var i, j;
        var cbs = {};

        var modules = backend.modules;
        var nodeOps = backend.nodeOps;

        for (i = 0; i < hooks.length; ++i) {
            cbs[hooks[i]] = [];
            for (j = 0; j < modules.length; ++j) {
                if (isDef(modules[j][hooks[i]])) {
                    cbs[hooks[i]].push(modules[j][hooks[i]]);
                }
            }
        }

        function emptyNodeAt (elm) {
            return new VNode(nodeOps.tagName(elm).toLowerCase(), {}, [], undefined, elm)
        }

        function createRmCb (childElm, listeners) {
            function remove$$1 () {
                if (--remove$$1.listeners === 0) {
                    removeNode(childElm);
                }
            }
            remove$$1.listeners = listeners;
            return remove$$1
        }

        function removeNode (el) {
            var parent = nodeOps.parentNode(el);
            // element may have already been removed due to v-html / v-text
            if (isDef(parent)) {
                nodeOps.removeChild(parent, el);
            }
        }

        function isUnknownElement$$1 (vnode, inVPre) {
            return (
                !inVPre &&
                !vnode.ns &&
                !(
                    config.ignoredElements.length &&
                    config.ignoredElements.some(function (ignore) {
                        return isRegExp(ignore)
                            ? ignore.test(vnode.tag)
                            : ignore === vnode.tag
                    })
                ) &&
                config.isUnknownElement(vnode.tag)
            )
        }

        var creatingElmInVPre = 0;

        function createElm (
            vnode,
            insertedVnodeQueue,
            parentElm,
            refElm,
            nested,
            ownerArray,
            index
        ) {
            if (isDef(vnode.elm) && isDef(ownerArray)) {
                // This vnode was used in a previous render!
                // now it's used as a new node, overwriting its elm would cause
                // potential patch errors down the road when it's used as an insertion
                // reference node. Instead, we clone the node on-demand before creating
                // associated DOM element for it.
                vnode = ownerArray[index] = cloneVNode(vnode);
            }

            vnode.isRootInsert = !nested; // for transition enter check
            if (createComponent(vnode, insertedVnodeQueue, parentElm, refElm)) {
                return
            }

            var data = vnode.data;
            var children = vnode.children;
            var tag = vnode.tag;
            if (isDef(tag)) {
                {
                    if (data && data.pre) {
                        creatingElmInVPre++;
                    }
                    if (isUnknownElement$$1(vnode, creatingElmInVPre)) {
                        warn(
                            'Unknown custom element: <' + tag + '> - did you ' +
                            'register the component correctly? For recursive components, ' +
                            'make sure to provide the "name" option.',
                            vnode.context
                        );
                    }
                }

                vnode.elm = vnode.ns
                    ? nodeOps.createElementNS(vnode.ns, tag)
                    : nodeOps.createElement(tag, vnode);
                setScope(vnode);

                /* istanbul ignore if */
                {
                    createChildren(vnode, children, insertedVnodeQueue);
                    if (isDef(data)) {
                        invokeCreateHooks(vnode, insertedVnodeQueue);
                    }
                    insert(parentElm, vnode.elm, refElm);
                }

                if (data && data.pre) {
                    creatingElmInVPre--;
                }
            } else if (isTrue(vnode.isComment)) {
                vnode.elm = nodeOps.createComment(vnode.text);
                insert(parentElm, vnode.elm, refElm);
            } else {
                vnode.elm = nodeOps.createTextNode(vnode.text);
                insert(parentElm, vnode.elm, refElm);
            }
        }

        function createComponent (vnode, insertedVnodeQueue, parentElm, refElm) {
            var i = vnode.data;
            if (isDef(i)) {
                var isReactivated = isDef(vnode.componentInstance) && i.keepAlive;
                if (isDef(i = i.hook) && isDef(i = i.init)) {
                    i(vnode, false /* hydrating */);
                }
                // after calling the init hook, if the vnode is a child component
                // it should've created a child instance and mounted it. the child
                // component also has set the placeholder vnode's elm.
                // in that case we can just return the element and be done.
                if (isDef(vnode.componentInstance)) {
                    initComponent(vnode, insertedVnodeQueue);
                    insert(parentElm, vnode.elm, refElm);
                    if (isTrue(isReactivated)) {
                        reactivateComponent(vnode, insertedVnodeQueue, parentElm, refElm);
                    }
                    return true
                }
            }
        }

        function initComponent (vnode, insertedVnodeQueue) {
            if (isDef(vnode.data.pendingInsert)) {
                insertedVnodeQueue.push.apply(insertedVnodeQueue, vnode.data.pendingInsert);
                vnode.data.pendingInsert = null;
            }
            vnode.elm = vnode.componentInstance.$el;
            if (isPatchable(vnode)) {
                invokeCreateHooks(vnode, insertedVnodeQueue);
                setScope(vnode);
            } else {
                // empty component root.
                // skip all element-related modules except for ref (#3455)
                registerRef(vnode);
                // make sure to invoke the insert hook
                insertedVnodeQueue.push(vnode);
            }
        }

        function reactivateComponent (vnode, insertedVnodeQueue, parentElm, refElm) {
            var i;
            // hack for #4339: a reactivated component with inner transition
            // does not trigger because the inner node's created hooks are not called
            // again. It's not ideal to involve module-specific logic in here but
            // there doesn't seem to be a better way to do it.
            var innerNode = vnode;
            while (innerNode.componentInstance) {
                innerNode = innerNode.componentInstance._vnode;
                if (isDef(i = innerNode.data) && isDef(i = i.transition)) {
                    for (i = 0; i < cbs.activate.length; ++i) {
                        cbs.activate[i](emptyNode, innerNode);
                    }
                    insertedVnodeQueue.push(innerNode);
                    break
                }
            }
            // unlike a newly created component,
            // a reactivated keep-alive component doesn't insert itself
            insert(parentElm, vnode.elm, refElm);
        }

        function insert (parent, elm, ref$$1) {
            if (isDef(parent)) {
                if (isDef(ref$$1)) {
                    if (nodeOps.parentNode(ref$$1) === parent) {
                        nodeOps.insertBefore(parent, elm, ref$$1);
                    }
                } else {
                    nodeOps.appendChild(parent, elm);
                }
            }
        }

        function createChildren (vnode, children, insertedVnodeQueue) {
            if (Array.isArray(children)) {
                {
                    checkDuplicateKeys(children);
                }
                for (var i = 0; i < children.length; ++i) {
                    createElm(children[i], insertedVnodeQueue, vnode.elm, null, true, children, i);
                }
            } else if (isPrimitive(vnode.text)) {
                nodeOps.appendChild(vnode.elm, nodeOps.createTextNode(String(vnode.text)));
            }
        }

        function isPatchable (vnode) {
            while (vnode.componentInstance) {
                vnode = vnode.componentInstance._vnode;
            }
            return isDef(vnode.tag)
        }

        function invokeCreateHooks (vnode, insertedVnodeQueue) {
            for (var i$1 = 0; i$1 < cbs.create.length; ++i$1) {
                cbs.create[i$1](emptyNode, vnode);
            }
            i = vnode.data.hook; // Reuse variable
            if (isDef(i)) {
                if (isDef(i.create)) { i.create(emptyNode, vnode); }
                if (isDef(i.insert)) { insertedVnodeQueue.push(vnode); }
            }
        }

        // set scope id attribute for scoped CSS.
        // this is implemented as a special case to avoid the overhead
        // of going through the normal attribute patching process.
        function setScope (vnode) {
            var i;
            if (isDef(i = vnode.fnScopeId)) {
                nodeOps.setStyleScope(vnode.elm, i);
            } else {
                var ancestor = vnode;
                while (ancestor) {
                    if (isDef(i = ancestor.context) && isDef(i = i.$options._scopeId)) {
                        nodeOps.setStyleScope(vnode.elm, i);
                    }
                    ancestor = ancestor.parent;
                }
            }
            // for slot content they should also get the scopeId from the host instance.
            if (isDef(i = activeInstance) &&
                i !== vnode.context &&
                i !== vnode.fnContext &&
                isDef(i = i.$options._scopeId)
            ) {
                nodeOps.setStyleScope(vnode.elm, i);
            }
        }

        function addVnodes (parentElm, refElm, vnodes, startIdx, endIdx, insertedVnodeQueue) {
            for (; startIdx <= endIdx; ++startIdx) {
                createElm(vnodes[startIdx], insertedVnodeQueue, parentElm, refElm, false, vnodes, startIdx);
            }
        }

        function invokeDestroyHook (vnode) {
            var i, j;
            var data = vnode.data;
            if (isDef(data)) {
                if (isDef(i = data.hook) && isDef(i = i.destroy)) { i(vnode); }
                for (i = 0; i < cbs.destroy.length; ++i) { cbs.destroy[i](vnode); }
            }
            if (isDef(i = vnode.children)) {
                for (j = 0; j < vnode.children.length; ++j) {
                    invokeDestroyHook(vnode.children[j]);
                }
            }
        }

        function removeVnodes (parentElm, vnodes, startIdx, endIdx) {
            for (; startIdx <= endIdx; ++startIdx) {
                var ch = vnodes[startIdx];
                if (isDef(ch)) {
                    if (isDef(ch.tag)) {
                        removeAndInvokeRemoveHook(ch);
                        invokeDestroyHook(ch);
                    } else { // Text node
                        removeNode(ch.elm);
                    }
                }
            }
        }

        function removeAndInvokeRemoveHook (vnode, rm) {
            if (isDef(rm) || isDef(vnode.data)) {
                var i;
                var listeners = cbs.remove.length + 1;
                if (isDef(rm)) {
                    // we have a recursively passed down rm callback
                    // increase the listeners count
                    rm.listeners += listeners;
                } else {
                    // directly removing
                    rm = createRmCb(vnode.elm, listeners);
                }
                // recursively invoke hooks on child component root node
                if (isDef(i = vnode.componentInstance) && isDef(i = i._vnode) && isDef(i.data)) {
                    removeAndInvokeRemoveHook(i, rm);
                }
                for (i = 0; i < cbs.remove.length; ++i) {
                    cbs.remove[i](vnode, rm);
                }
                if (isDef(i = vnode.data.hook) && isDef(i = i.remove)) {
                    i(vnode, rm);
                } else {
                    rm();
                }
            } else {
                removeNode(vnode.elm);
            }
        }

        function updateChildren (parentElm, oldCh, newCh, insertedVnodeQueue, removeOnly) {
            var oldStartIdx = 0;
            var newStartIdx = 0;
            var oldEndIdx = oldCh.length - 1;
            var oldStartVnode = oldCh[0];
            var oldEndVnode = oldCh[oldEndIdx];
            var newEndIdx = newCh.length - 1;
            var newStartVnode = newCh[0];
            var newEndVnode = newCh[newEndIdx];
            var oldKeyToIdx, idxInOld, vnodeToMove, refElm;

            // removeOnly is a special flag used only by <transition-group>
            // to ensure removed elements stay in correct relative positions
            // during leaving transitions
            var canMove = !removeOnly;

            {
                checkDuplicateKeys(newCh);
            }

            while (oldStartIdx <= oldEndIdx && newStartIdx <= newEndIdx) {
                if (isUndef(oldStartVnode)) {
                    oldStartVnode = oldCh[++oldStartIdx]; // Vnode has been moved left
                } else if (isUndef(oldEndVnode)) {
                    oldEndVnode = oldCh[--oldEndIdx];
                } else if (sameVnode(oldStartVnode, newStartVnode)) {
                    patchVnode(oldStartVnode, newStartVnode, insertedVnodeQueue, newCh, newStartIdx);
                    oldStartVnode = oldCh[++oldStartIdx];
                    newStartVnode = newCh[++newStartIdx];
                } else if (sameVnode(oldEndVnode, newEndVnode)) {
                    patchVnode(oldEndVnode, newEndVnode, insertedVnodeQueue, newCh, newEndIdx);
                    oldEndVnode = oldCh[--oldEndIdx];
                    newEndVnode = newCh[--newEndIdx];
                } else if (sameVnode(oldStartVnode, newEndVnode)) { // Vnode moved right
                    patchVnode(oldStartVnode, newEndVnode, insertedVnodeQueue, newCh, newEndIdx);
                    canMove && nodeOps.insertBefore(parentElm, oldStartVnode.elm, nodeOps.nextSibling(oldEndVnode.elm));
                    oldStartVnode = oldCh[++oldStartIdx];
                    newEndVnode = newCh[--newEndIdx];
                } else if (sameVnode(oldEndVnode, newStartVnode)) { // Vnode moved left
                    patchVnode(oldEndVnode, newStartVnode, insertedVnodeQueue, newCh, newStartIdx);
                    canMove && nodeOps.insertBefore(parentElm, oldEndVnode.elm, oldStartVnode.elm);
                    oldEndVnode = oldCh[--oldEndIdx];
                    newStartVnode = newCh[++newStartIdx];
                } else {
                    if (isUndef(oldKeyToIdx)) { oldKeyToIdx = createKeyToOldIdx(oldCh, oldStartIdx, oldEndIdx); }
                    idxInOld = isDef(newStartVnode.key)
                        ? oldKeyToIdx[newStartVnode.key]
                        : findIdxInOld(newStartVnode, oldCh, oldStartIdx, oldEndIdx);
                    if (isUndef(idxInOld)) { // New element
                        createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm, false, newCh, newStartIdx);
                    } else {
                        vnodeToMove = oldCh[idxInOld];
                        if (sameVnode(vnodeToMove, newStartVnode)) {
                            patchVnode(vnodeToMove, newStartVnode, insertedVnodeQueue, newCh, newStartIdx);
                            oldCh[idxInOld] = undefined;
                            canMove && nodeOps.insertBefore(parentElm, vnodeToMove.elm, oldStartVnode.elm);
                        } else {
                            // same key but different element. treat as new element
                            createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm, false, newCh, newStartIdx);
                        }
                    }
                    newStartVnode = newCh[++newStartIdx];
                }
            }
            if (oldStartIdx > oldEndIdx) {
                refElm = isUndef(newCh[newEndIdx + 1]) ? null : newCh[newEndIdx + 1].elm;
                addVnodes(parentElm, refElm, newCh, newStartIdx, newEndIdx, insertedVnodeQueue);
            } else if (newStartIdx > newEndIdx) {
                removeVnodes(parentElm, oldCh, oldStartIdx, oldEndIdx);
            }
        }

        function checkDuplicateKeys (children) {
            var seenKeys = {};
            for (var i = 0; i < children.length; i++) {
                var vnode = children[i];
                var key = vnode.key;
                if (isDef(key)) {
                    if (seenKeys[key]) {
                        warn(
                            ("Duplicate keys detected: '" + key + "'. This may cause an update error."),
                            vnode.context
                        );
                    } else {
                        seenKeys[key] = true;
                    }
                }
            }
        }

        function findIdxInOld (node, oldCh, start, end) {
            for (var i = start; i < end; i++) {
                var c = oldCh[i];
                if (isDef(c) && sameVnode(node, c)) { return i }
            }
        }

        function patchVnode (
            oldVnode,
            vnode,
            insertedVnodeQueue,
            ownerArray,
            index,
            removeOnly
        ) {
            if (oldVnode === vnode) {
                return
            }

            if (isDef(vnode.elm) && isDef(ownerArray)) {
                // clone reused vnode
                vnode = ownerArray[index] = cloneVNode(vnode);
            }

            var elm = vnode.elm = oldVnode.elm;

            if (isTrue(oldVnode.isAsyncPlaceholder)) {
                if (isDef(vnode.asyncFactory.resolved)) {
                    hydrate(oldVnode.elm, vnode, insertedVnodeQueue);
                } else {
                    vnode.isAsyncPlaceholder = true;
                }
                return
            }

            // reuse element for static trees.
            // note we only do this if the vnode is cloned -
            // if the new node is not cloned it means the render functions have been
            // reset by the hot-reload-api and we need to do a proper re-render.
            if (isTrue(vnode.isStatic) &&
                isTrue(oldVnode.isStatic) &&
                vnode.key === oldVnode.key &&
                (isTrue(vnode.isCloned) || isTrue(vnode.isOnce))
            ) {
                vnode.componentInstance = oldVnode.componentInstance;
                return
            }

            var i;
            var data = vnode.data;
            if (isDef(data) && isDef(i = data.hook) && isDef(i = i.prepatch)) {
                i(oldVnode, vnode);
            }

            var oldCh = oldVnode.children;
            var ch = vnode.children;
            if (isDef(data) && isPatchable(vnode)) {
                for (i = 0; i < cbs.update.length; ++i) { cbs.update[i](oldVnode, vnode); }
                if (isDef(i = data.hook) && isDef(i = i.update)) { i(oldVnode, vnode); }
            }
            if (isUndef(vnode.text)) {
                if (isDef(oldCh) && isDef(ch)) {
                    if (oldCh !== ch) { updateChildren(elm, oldCh, ch, insertedVnodeQueue, removeOnly); }
                } else if (isDef(ch)) {
                    {
                        checkDuplicateKeys(ch);
                    }
                    if (isDef(oldVnode.text)) { nodeOps.setTextContent(elm, ''); }
                    addVnodes(elm, null, ch, 0, ch.length - 1, insertedVnodeQueue);
                } else if (isDef(oldCh)) {
                    removeVnodes(elm, oldCh, 0, oldCh.length - 1);
                } else if (isDef(oldVnode.text)) {
                    nodeOps.setTextContent(elm, '');
                }
            } else if (oldVnode.text !== vnode.text) {
                nodeOps.setTextContent(elm, vnode.text);
            }
            if (isDef(data)) {
                if (isDef(i = data.hook) && isDef(i = i.postpatch)) { i(oldVnode, vnode); }
            }
        }

        function invokeInsertHook (vnode, queue, initial) {
            // delay insert hooks for component root nodes, invoke them after the
            // element is really inserted
            if (isTrue(initial) && isDef(vnode.parent)) {
                vnode.parent.data.pendingInsert = queue;
            } else {
                for (var i = 0; i < queue.length; ++i) {
                    queue[i].data.hook.insert(queue[i]);
                }
            }
        }

        var hydrationBailed = false;
        // list of modules that can skip create hook during hydration because they
        // are already rendered on the client or has no need for initialization
        // Note: style is excluded because it relies on initial clone for future
        // deep updates (#7063).
        var isRenderedModule = makeMap('attrs,class,staticClass,staticStyle,key');

        // Note: this is a browser-only function so we can assume elms are DOM nodes.
        function hydrate (elm, vnode, insertedVnodeQueue, inVPre) {
            var i;
            var tag = vnode.tag;
            var data = vnode.data;
            var children = vnode.children;
            inVPre = inVPre || (data && data.pre);
            vnode.elm = elm;

            if (isTrue(vnode.isComment) && isDef(vnode.asyncFactory)) {
                vnode.isAsyncPlaceholder = true;
                return true
            }
            // assert node match
            {
                if (!assertNodeMatch(elm, vnode, inVPre)) {
                    return false
                }
            }
            if (isDef(data)) {
                if (isDef(i = data.hook) && isDef(i = i.init)) { i(vnode, true /* hydrating */); }
                if (isDef(i = vnode.componentInstance)) {
                    // child component. it should have hydrated its own tree.
                    initComponent(vnode, insertedVnodeQueue);
                    return true
                }
            }
            if (isDef(tag)) {
                if (isDef(children)) {
                    // empty element, allow client to pick up and populate children
                    if (!elm.hasChildNodes()) {
                        createChildren(vnode, children, insertedVnodeQueue);
                    } else {
                        // v-html and domProps: innerHTML
                        if (isDef(i = data) && isDef(i = i.domProps) && isDef(i = i.innerHTML)) {
                            if (i !== elm.innerHTML) {
                                /* istanbul ignore if */
                                if (typeof console !== 'undefined' &&
                                    !hydrationBailed
                                ) {
                                    hydrationBailed = true;
                                    console.warn('Parent: ', elm);
                                    console.warn('server innerHTML: ', i);
                                    console.warn('client innerHTML: ', elm.innerHTML);
                                }
                                return false
                            }
                        } else {
                            // iterate and compare children lists
                            var childrenMatch = true;
                            var childNode = elm.firstChild;
                            for (var i$1 = 0; i$1 < children.length; i$1++) {
                                if (!childNode || !hydrate(childNode, children[i$1], insertedVnodeQueue, inVPre)) {
                                    childrenMatch = false;
                                    break
                                }
                                childNode = childNode.nextSibling;
                            }
                            // if childNode is not null, it means the actual childNodes list is
                            // longer than the virtual children list.
                            if (!childrenMatch || childNode) {
                                /* istanbul ignore if */
                                if (typeof console !== 'undefined' &&
                                    !hydrationBailed
                                ) {
                                    hydrationBailed = true;
                                    console.warn('Parent: ', elm);
                                    console.warn('Mismatching childNodes vs. VNodes: ', elm.childNodes, children);
                                }
                                return false
                            }
                        }
                    }
                }
                if (isDef(data)) {
                    var fullInvoke = false;
                    for (var key in data) {
                        if (!isRenderedModule(key)) {
                            fullInvoke = true;
                            invokeCreateHooks(vnode, insertedVnodeQueue);
                            break
                        }
                    }
                    if (!fullInvoke && data['class']) {
                        // ensure collecting deps for deep class bindings for future updates
                        traverse(data['class']);
                    }
                }
            } else if (elm.data !== vnode.text) {
                elm.data = vnode.text;
            }
            return true
        }

        function assertNodeMatch (node, vnode, inVPre) {
            if (isDef(vnode.tag)) {
                return vnode.tag.indexOf('vue-component') === 0 || (
                        !isUnknownElement$$1(vnode, inVPre) &&
                        vnode.tag.toLowerCase() === (node.tagName && node.tagName.toLowerCase())
                    )
            } else {
                return node.nodeType === (vnode.isComment ? 8 : 3)
            }
        }

        return function patch (oldVnode, vnode, hydrating, removeOnly) {
            if (isUndef(vnode)) {
                if (isDef(oldVnode)) { invokeDestroyHook(oldVnode); }
                return
            }

            var isInitialPatch = false;
            var insertedVnodeQueue = [];

            if (isUndef(oldVnode)) {
                // empty mount (likely as component), create new root element
                isInitialPatch = true;
                createElm(vnode, insertedVnodeQueue);
            } else {
                var isRealElement = isDef(oldVnode.nodeType);
                if (!isRealElement && sameVnode(oldVnode, vnode)) {
                    // patch existing root node
                    patchVnode(oldVnode, vnode, insertedVnodeQueue, null, null, removeOnly);
                } else {
                    if (isRealElement) {
                        // mounting to a real element
                        // check if this is server-rendered content and if we can perform
                        // a successful hydration.
                        if (oldVnode.nodeType === 1 && oldVnode.hasAttribute(SSR_ATTR)) {
                            oldVnode.removeAttribute(SSR_ATTR);
                            hydrating = true;
                        }
                        if (isTrue(hydrating)) {
                            if (hydrate(oldVnode, vnode, insertedVnodeQueue)) {
                                invokeInsertHook(vnode, insertedVnodeQueue, true);
                                return oldVnode
                            } else {
                                warn(
                                    'The client-side rendered virtual DOM tree is not matching ' +
                                    'server-rendered content. This is likely caused by incorrect ' +
                                    'HTML markup, for example nesting block-level elements inside ' +
                                    '<p>, or missing <tbody>. Bailing hydration and performing ' +
                                    'full client-side render.'
                                );
                            }
                        }
                        // either not server-rendered, or hydration failed.
                        // create an empty node and replace it
                        oldVnode = emptyNodeAt(oldVnode);
                    }

                    // replacing existing element
                    var oldElm = oldVnode.elm;
                    var parentElm = nodeOps.parentNode(oldElm);

                    // create new node
                    createElm(
                        vnode,
                        insertedVnodeQueue,
                        // extremely rare edge case: do not insert if old element is in a
                        // leaving transition. Only happens when combining transition +
                        // keep-alive + HOCs. (#4590)
                        oldElm._leaveCb ? null : parentElm,
                        nodeOps.nextSibling(oldElm)
                    );

                    // update parent placeholder node element, recursively
                    if (isDef(vnode.parent)) {
                        var ancestor = vnode.parent;
                        var patchable = isPatchable(vnode);
                        while (ancestor) {
                            for (var i = 0; i < cbs.destroy.length; ++i) {
                                cbs.destroy[i](ancestor);
                            }
                            ancestor.elm = vnode.elm;
                            if (patchable) {
                                for (var i$1 = 0; i$1 < cbs.create.length; ++i$1) {
                                    cbs.create[i$1](emptyNode, ancestor);
                                }
                                // #6513
                                // invoke insert hooks that may have been merged by create hooks.
                                // e.g. for directives that uses the "inserted" hook.
                                var insert = ancestor.data.hook.insert;
                                if (insert.merged) {
                                    // start at index 1 to avoid re-invoking component mounted hook
                                    for (var i$2 = 1; i$2 < insert.fns.length; i$2++) {
                                        insert.fns[i$2]();
                                    }
                                }
                            } else {
                                registerRef(ancestor);
                            }
                            ancestor = ancestor.parent;
                        }
                    }

                    // destroy old node
                    if (isDef(parentElm)) {
                        removeVnodes(parentElm, [oldVnode], 0, 0);
                    } else if (isDef(oldVnode.tag)) {
                        invokeDestroyHook(oldVnode);
                    }
                }
            }

            invokeInsertHook(vnode, insertedVnodeQueue, isInitialPatch);
            return vnode.elm
        }
    }

    /*  */

    var directives = {
        create: updateDirectives,
        update: updateDirectives,
        destroy: function unbindDirectives (vnode) {
            updateDirectives(vnode, emptyNode);
        }
    };

    function updateDirectives (oldVnode, vnode) {
        if (oldVnode.data.directives || vnode.data.directives) {
            _update(oldVnode, vnode);
        }
    }

    function _update (oldVnode, vnode) {
        var isCreate = oldVnode === emptyNode;
        var isDestroy = vnode === emptyNode;
        var oldDirs = normalizeDirectives$1(oldVnode.data.directives, oldVnode.context);
        var newDirs = normalizeDirectives$1(vnode.data.directives, vnode.context);

        var dirsWithInsert = [];
        var dirsWithPostpatch = [];

        var key, oldDir, dir;
        for (key in newDirs) {
            oldDir = oldDirs[key];
            dir = newDirs[key];
            if (!oldDir) {
                // new directive, bind
                callHook$1(dir, 'bind', vnode, oldVnode);
                if (dir.def && dir.def.inserted) {
                    dirsWithInsert.push(dir);
                }
            } else {
                // existing directive, update
                dir.oldValue = oldDir.value;
                dir.oldArg = oldDir.arg;
                callHook$1(dir, 'update', vnode, oldVnode);
                if (dir.def && dir.def.componentUpdated) {
                    dirsWithPostpatch.push(dir);
                }
            }
        }

        if (dirsWithInsert.length) {
            var callInsert = function () {
                for (var i = 0; i < dirsWithInsert.length; i++) {
                    callHook$1(dirsWithInsert[i], 'inserted', vnode, oldVnode);
                }
            };
            if (isCreate) {
                mergeVNodeHook(vnode, 'insert', callInsert);
            } else {
                callInsert();
            }
        }

        if (dirsWithPostpatch.length) {
            mergeVNodeHook(vnode, 'postpatch', function () {
                for (var i = 0; i < dirsWithPostpatch.length; i++) {
                    callHook$1(dirsWithPostpatch[i], 'componentUpdated', vnode, oldVnode);
                }
            });
        }

        if (!isCreate) {
            for (key in oldDirs) {
                if (!newDirs[key]) {
                    // no longer present, unbind
                    callHook$1(oldDirs[key], 'unbind', oldVnode, oldVnode, isDestroy);
                }
            }
        }
    }

    var emptyModifiers = Object.create(null);

    function normalizeDirectives$1 (
        dirs,
        vm
    ) {
        var res = Object.create(null);
        if (!dirs) {
            // $flow-disable-line
            return res
        }
        var i, dir;
        for (i = 0; i < dirs.length; i++) {
            dir = dirs[i];
            if (!dir.modifiers) {
                // $flow-disable-line
                dir.modifiers = emptyModifiers;
            }
            res[getRawDirName(dir)] = dir;
            dir.def = resolveAsset(vm.$options, 'directives', dir.name, true);
        }
        // $flow-disable-line
        return res
    }

    function getRawDirName (dir) {
        return dir.rawName || ((dir.name) + "." + (Object.keys(dir.modifiers || {}).join('.')))
    }

    function callHook$1 (dir, hook, vnode, oldVnode, isDestroy) {
        var fn = dir.def && dir.def[hook];
        if (fn) {
            try {
                fn(vnode.elm, dir, vnode, oldVnode, isDestroy);
            } catch (e) {
                handleError(e, vnode.context, ("directive " + (dir.name) + " " + hook + " hook"));
            }
        }
    }

    var baseModules = [
        ref,
        directives
    ];

    /*  */

    function updateAttrs (oldVnode, vnode) {
        var opts = vnode.componentOptions;
        if (isDef(opts) && opts.Ctor.options.inheritAttrs === false) {
            return
        }
        if (isUndef(oldVnode.data.attrs) && isUndef(vnode.data.attrs)) {
            return
        }
        var key, cur, old;
        var elm = vnode.elm;
        var oldAttrs = oldVnode.data.attrs || {};
        var attrs = vnode.data.attrs || {};
        // clone observed objects, as the user probably wants to mutate it
        if (isDef(attrs.__ob__)) {
            attrs = vnode.data.attrs = extend({}, attrs);
        }

        for (key in attrs) {
            cur = attrs[key];
            old = oldAttrs[key];
            if (old !== cur) {
                setAttr(elm, key, cur);
            }
        }
        // #4391: in IE9, setting type can reset value for input[type=radio]
        // #6666: IE/Edge forces progress value down to 1 before setting a max
        /* istanbul ignore if */
        if ((isIE || isEdge) && attrs.value !== oldAttrs.value) {
            setAttr(elm, 'value', attrs.value);
        }
        for (key in oldAttrs) {
            if (isUndef(attrs[key])) {
                if (isXlink(key)) {
                    elm.removeAttributeNS(xlinkNS, getXlinkProp(key));
                } else if (!isEnumeratedAttr(key)) {
                    elm.removeAttribute(key);
                }
            }
        }
    }

    function setAttr (el, key, value) {
        if (el.tagName.indexOf('-') > -1) {
            baseSetAttr(el, key, value);
        } else if (isBooleanAttr(key)) {
            // set attribute for blank value
            // e.g. <option disabled>Select one</option>
            if (isFalsyAttrValue(value)) {
                el.removeAttribute(key);
            } else {
                // technically allowfullscreen is a boolean attribute for <iframe>,
                // but Flash expects a value of "true" when used on <embed> tag
                value = key === 'allowfullscreen' && el.tagName === 'EMBED'
                    ? 'true'
                    : key;
                el.setAttribute(key, value);
            }
        } else if (isEnumeratedAttr(key)) {
            el.setAttribute(key, convertEnumeratedValue(key, value));
        } else if (isXlink(key)) {
            if (isFalsyAttrValue(value)) {
                el.removeAttributeNS(xlinkNS, getXlinkProp(key));
            } else {
                el.setAttributeNS(xlinkNS, key, value);
            }
        } else {
            baseSetAttr(el, key, value);
        }
    }

    function baseSetAttr (el, key, value) {
        if (isFalsyAttrValue(value)) {
            el.removeAttribute(key);
        } else {
            // #7138: IE10 & 11 fires input event when setting placeholder on
            // <textarea>... block the first input event and remove the blocker
            // immediately.
            /* istanbul ignore if */
            if (
                isIE && !isIE9 &&
                el.tagName === 'TEXTAREA' &&
                key === 'placeholder' && value !== '' && !el.__ieph
            ) {
                var blocker = function (e) {
                    e.stopImmediatePropagation();
                    el.removeEventListener('input', blocker);
                };
                el.addEventListener('input', blocker);
                // $flow-disable-line
                el.__ieph = true; /* IE placeholder patched */
            }
            el.setAttribute(key, value);
        }
    }

    var attrs = {
        create: updateAttrs,
        update: updateAttrs
    };

    /*  */

    function updateClass (oldVnode, vnode) {
        var el = vnode.elm;
        var data = vnode.data;
        var oldData = oldVnode.data;
        if (
            isUndef(data.staticClass) &&
            isUndef(data.class) && (
                isUndef(oldData) || (
                    isUndef(oldData.staticClass) &&
                    isUndef(oldData.class)
                )
            )
        ) {
            return
        }

        var cls = genClassForVnode(vnode);

        // handle transition classes
        var transitionClass = el._transitionClasses;
        if (isDef(transitionClass)) {
            cls = concat(cls, stringifyClass(transitionClass));
        }

        // set the class
        if (cls !== el._prevClass) {
            el.setAttribute('class', cls);
            el._prevClass = cls;
        }
    }

    var klass = {
        create: updateClass,
        update: updateClass
    };

    /*  */

    var validDivisionCharRE = /[\w).+\-_$\]]/;

    function parseFilters (exp) {
        var inSingle = false;
        var inDouble = false;
        var inTemplateString = false;
        var inRegex = false;
        var curly = 0;
        var square = 0;
        var paren = 0;
        var lastFilterIndex = 0;
        var c, prev, i, expression, filters;

        for (i = 0; i < exp.length; i++) {
            prev = c;
            c = exp.charCodeAt(i);
            if (inSingle) {
                if (c === 0x27 && prev !== 0x5C) { inSingle = false; }
            } else if (inDouble) {
                if (c === 0x22 && prev !== 0x5C) { inDouble = false; }
            } else if (inTemplateString) {
                if (c === 0x60 && prev !== 0x5C) { inTemplateString = false; }
            } else if (inRegex) {
                if (c === 0x2f && prev !== 0x5C) { inRegex = false; }
            } else if (
                c === 0x7C && // pipe
                exp.charCodeAt(i + 1) !== 0x7C &&
                exp.charCodeAt(i - 1) !== 0x7C &&
                !curly && !square && !paren
            ) {
                if (expression === undefined) {
                    // first filter, end of expression
                    lastFilterIndex = i + 1;
                    expression = exp.slice(0, i).trim();
                } else {
                    pushFilter();
                }
            } else {
                switch (c) {
                    case 0x22: inDouble = true; break         // "
                    case 0x27: inSingle = true; break         // '
                    case 0x60: inTemplateString = true; break // `
                    case 0x28: paren++; break                 // (
                    case 0x29: paren--; break                 // )
                    case 0x5B: square++; break                // [
                    case 0x5D: square--; break                // ]
                    case 0x7B: curly++; break                 // {
                    case 0x7D: curly--; break                 // }
                }
                if (c === 0x2f) { // /
                    var j = i - 1;
                    var p = (void 0);
                    // find first non-whitespace prev char
                    for (; j >= 0; j--) {
                        p = exp.charAt(j);
                        if (p !== ' ') { break }
                    }
                    if (!p || !validDivisionCharRE.test(p)) {
                        inRegex = true;
                    }
                }
            }
        }

        if (expression === undefined) {
            expression = exp.slice(0, i).trim();
        } else if (lastFilterIndex !== 0) {
            pushFilter();
        }

        function pushFilter () {
            (filters || (filters = [])).push(exp.slice(lastFilterIndex, i).trim());
            lastFilterIndex = i + 1;
        }

        if (filters) {
            for (i = 0; i < filters.length; i++) {
                expression = wrapFilter(expression, filters[i]);
            }
        }

        return expression
    }

    function wrapFilter (exp, filter) {
        var i = filter.indexOf('(');
        if (i < 0) {
            // _f: resolveFilter
            return ("_f(\"" + filter + "\")(" + exp + ")")
        } else {
            var name = filter.slice(0, i);
            var args = filter.slice(i + 1);
            return ("_f(\"" + name + "\")(" + exp + (args !== ')' ? ',' + args : args))
        }
    }

    /*  */



    /* eslint-disable no-unused-vars */
    function baseWarn (msg, range) {
        console.error(("[Vue compiler]: " + msg));
    }
    /* eslint-enable no-unused-vars */

    function pluckModuleFunction (
        modules,
        key
    ) {
        return modules
            ? modules.map(function (m) { return m[key]; }).filter(function (_) { return _; })
            : []
    }

    function addProp (el, name, value, range, dynamic) {
        (el.props || (el.props = [])).push(rangeSetItem({ name: name, value: value, dynamic: dynamic }, range));
        el.plain = false;
    }

    function addAttr (el, name, value, range, dynamic) {
        var attrs = dynamic
            ? (el.dynamicAttrs || (el.dynamicAttrs = []))
            : (el.attrs || (el.attrs = []));
        attrs.push(rangeSetItem({ name: name, value: value, dynamic: dynamic }, range));
        el.plain = false;
    }

    // add a raw attr (use this in preTransforms)
    function addRawAttr (el, name, value, range) {
        el.attrsMap[name] = value;
        el.attrsList.push(rangeSetItem({ name: name, value: value }, range));
    }

    function addDirective (
        el,
        name,
        rawName,
        value,
        arg,
        isDynamicArg,
        modifiers,
        range
    ) {
        (el.directives || (el.directives = [])).push(rangeSetItem({
            name: name,
            rawName: rawName,
            value: value,
            arg: arg,
            isDynamicArg: isDynamicArg,
            modifiers: modifiers
        }, range));
        el.plain = false;
    }

    function prependModifierMarker (symbol, name, dynamic) {
        return dynamic
            ? ("_p(" + name + ",\"" + symbol + "\")")
            : symbol + name // mark the event as captured
    }

    function addHandler (
        el,
        name,
        value,
        modifiers,
        important,
        warn,
        range,
        dynamic
    ) {
        modifiers = modifiers || emptyObject;
        // warn prevent and passive modifier
        /* istanbul ignore if */
        if (
            warn &&
            modifiers.prevent && modifiers.passive
        ) {
            warn(
                'passive and prevent can\'t be used together. ' +
                'Passive handler can\'t prevent default event.',
                range
            );
        }

        // normalize click.right and click.middle since they don't actually fire
        // this is technically browser-specific, but at least for now browsers are
        // the only target envs that have right/middle clicks.
        if (modifiers.right) {
            if (dynamic) {
                name = "(" + name + ")==='click'?'contextmenu':(" + name + ")";
            } else if (name === 'click') {
                name = 'contextmenu';
                delete modifiers.right;
            }
        } else if (modifiers.middle) {
            if (dynamic) {
                name = "(" + name + ")==='click'?'mouseup':(" + name + ")";
            } else if (name === 'click') {
                name = 'mouseup';
            }
        }

        // check capture modifier
        if (modifiers.capture) {
            delete modifiers.capture;
            name = prependModifierMarker('!', name, dynamic);
        }
        if (modifiers.once) {
            delete modifiers.once;
            name = prependModifierMarker('~', name, dynamic);
        }
        /* istanbul ignore if */
        if (modifiers.passive) {
            delete modifiers.passive;
            name = prependModifierMarker('&', name, dynamic);
        }

        var events;
        if (modifiers.native) {
            delete modifiers.native;
            events = el.nativeEvents || (el.nativeEvents = {});
        } else {
            events = el.events || (el.events = {});
        }

        var newHandler = rangeSetItem({ value: value.trim(), dynamic: dynamic }, range);
        if (modifiers !== emptyObject) {
            newHandler.modifiers = modifiers;
        }

        var handlers = events[name];
        /* istanbul ignore if */
        if (Array.isArray(handlers)) {
            important ? handlers.unshift(newHandler) : handlers.push(newHandler);
        } else if (handlers) {
            events[name] = important ? [newHandler, handlers] : [handlers, newHandler];
        } else {
            events[name] = newHandler;
        }

        el.plain = false;
    }

    function getRawBindingAttr (
        el,
        name
    ) {
        return el.rawAttrsMap[':' + name] ||
            el.rawAttrsMap['v-bind:' + name] ||
            el.rawAttrsMap[name]
    }

    function getBindingAttr (
        el,
        name,
        getStatic
    ) {
        var dynamicValue =
            getAndRemoveAttr(el, ':' + name) ||
            getAndRemoveAttr(el, 'v-bind:' + name);
        if (dynamicValue != null) {
            return parseFilters(dynamicValue)
        } else if (getStatic !== false) {
            var staticValue = getAndRemoveAttr(el, name);
            if (staticValue != null) {
                return JSON.stringify(staticValue)
            }
        }
    }

    // note: this only removes the attr from the Array (attrsList) so that it
    // doesn't get processed by processAttrs.
    // By default it does NOT remove it from the map (attrsMap) because the map is
    // needed during codegen.
    function getAndRemoveAttr (
        el,
        name,
        removeFromMap
    ) {
        var val;
        if ((val = el.attrsMap[name]) != null) {
            var list = el.attrsList;
            for (var i = 0, l = list.length; i < l; i++) {
                if (list[i].name === name) {
                    list.splice(i, 1);
                    break
                }
            }
        }
        if (removeFromMap) {
            delete el.attrsMap[name];
        }
        return val
    }

    function getAndRemoveAttrByRegex (
        el,
        name
    ) {
        var list = el.attrsList;
        for (var i = 0, l = list.length; i < l; i++) {
            var attr = list[i];
            if (name.test(attr.name)) {
                list.splice(i, 1);
                return attr
            }
        }
    }

    function rangeSetItem (
        item,
        range
    ) {
        if (range) {
            if (range.start != null) {
                item.start = range.start;
            }
            if (range.end != null) {
                item.end = range.end;
            }
        }
        return item
    }

    /*  */

    /**
     * Cross-platform code generation for component v-model
     */
    function genComponentModel (
        el,
        value,
        modifiers
    ) {
        var ref = modifiers || {};
        var number = ref.number;
        var trim = ref.trim;

        var baseValueExpression = '$$v';
        var valueExpression = baseValueExpression;
        if (trim) {
            valueExpression =
                "(typeof " + baseValueExpression + " === 'string'" +
                "? " + baseValueExpression + ".trim()" +
                ": " + baseValueExpression + ")";
        }
        if (number) {
            valueExpression = "_n(" + valueExpression + ")";
        }
        var assignment = genAssignmentCode(value, valueExpression);

        el.model = {
            value: ("(" + value + ")"),
            expression: JSON.stringify(value),
            callback: ("function (" + baseValueExpression + ") {" + assignment + "}")
        };
    }

    /**
     * Cross-platform codegen helper for generating v-model value assignment code.
     */
    function genAssignmentCode (
        value,
        assignment
    ) {
        var res = parseModel(value);
        if (res.key === null) {
            return (value + "=" + assignment)
        } else {
            return ("$set(" + (res.exp) + ", " + (res.key) + ", " + assignment + ")")
        }
    }

    /**
     * Parse a v-model expression into a base path and a final key segment.
     * Handles both dot-path and possible square brackets.
     *
     * Possible cases:
     *
     * - test
     * - test[key]
     * - test[test1[key]]
     * - test["a"][key]
     * - xxx.test[a[a].test1[key]]
     * - test.xxx.a["asa"][test1[key]]
     *
     */

    var len, str, chr, index$1, expressionPos, expressionEndPos;



    function parseModel (val) {
        // Fix https://github.com/vuejs/vue/pull/7730
        // allow v-model="obj.val " (trailing whitespace)
        val = val.trim();
        len = val.length;

        if (val.indexOf('[') < 0 || val.lastIndexOf(']') < len - 1) {
            index$1 = val.lastIndexOf('.');
            if (index$1 > -1) {
                return {
                    exp: val.slice(0, index$1),
                    key: '"' + val.slice(index$1 + 1) + '"'
                }
            } else {
                return {
                    exp: val,
                    key: null
                }
            }
        }

        str = val;
        index$1 = expressionPos = expressionEndPos = 0;

        while (!eof()) {
            chr = next();
            /* istanbul ignore if */
            if (isStringStart(chr)) {
                parseString(chr);
            } else if (chr === 0x5B) {
                parseBracket(chr);
            }
        }

        return {
            exp: val.slice(0, expressionPos),
            key: val.slice(expressionPos + 1, expressionEndPos)
        }
    }

    function next () {
        return str.charCodeAt(++index$1)
    }

    function eof () {
        return index$1 >= len
    }

    function isStringStart (chr) {
        return chr === 0x22 || chr === 0x27
    }

    function parseBracket (chr) {
        var inBracket = 1;
        expressionPos = index$1;
        while (!eof()) {
            chr = next();
            if (isStringStart(chr)) {
                parseString(chr);
                continue
            }
            if (chr === 0x5B) { inBracket++; }
            if (chr === 0x5D) { inBracket--; }
            if (inBracket === 0) {
                expressionEndPos = index$1;
                break
            }
        }
    }

    function parseString (chr) {
        var stringQuote = chr;
        while (!eof()) {
            chr = next();
            if (chr === stringQuote) {
                break
            }
        }
    }

    /*  */

    var warn$1;

    // in some cases, the event used has to be determined at runtime
    // so we used some reserved tokens during compile.
    var RANGE_TOKEN = '__r';
    var CHECKBOX_RADIO_TOKEN = '__c';

    function model (
        el,
        dir,
        _warn
    ) {
        warn$1 = _warn;
        var value = dir.value;
        var modifiers = dir.modifiers;
        var tag = el.tag;
        var type = el.attrsMap.type;

        {
            // inputs with type="file" are read only and setting the input's
            // value will throw an error.
            if (tag === 'input' && type === 'file') {
                warn$1(
                    "<" + (el.tag) + " v-model=\"" + value + "\" type=\"file\">:\n" +
                    "File inputs are read only. Use a v-on:change listener instead.",
                    el.rawAttrsMap['v-model']
                );
            }
        }

        if (el.component) {
            genComponentModel(el, value, modifiers);
            // component v-model doesn't need extra runtime
            return false
        } else if (tag === 'select') {
            genSelect(el, value, modifiers);
        } else if (tag === 'input' && type === 'checkbox') {
            genCheckboxModel(el, value, modifiers);
        } else if (tag === 'input' && type === 'radio') {
            genRadioModel(el, value, modifiers);
        } else if (tag === 'input' || tag === 'textarea') {
            genDefaultModel(el, value, modifiers);
        } else if (!config.isReservedTag(tag)) {
            genComponentModel(el, value, modifiers);
            // component v-model doesn't need extra runtime
            return false
        } else {
            warn$1(
                "<" + (el.tag) + " v-model=\"" + value + "\">: " +
                "v-model is not supported on this element type. " +
                'If you are working with contenteditable, it\'s recommended to ' +
                'wrap a library dedicated for that purpose inside a custom component.',
                el.rawAttrsMap['v-model']
            );
        }

        // ensure runtime directive metadata
        return true
    }

    function genCheckboxModel (
        el,
        value,
        modifiers
    ) {
        var number = modifiers && modifiers.number;
        var valueBinding = getBindingAttr(el, 'value') || 'null';
        var trueValueBinding = getBindingAttr(el, 'true-value') || 'true';
        var falseValueBinding = getBindingAttr(el, 'false-value') || 'false';
        addProp(el, 'checked',
            "Array.isArray(" + value + ")" +
            "?_i(" + value + "," + valueBinding + ")>-1" + (
                trueValueBinding === 'true'
                    ? (":(" + value + ")")
                    : (":_q(" + value + "," + trueValueBinding + ")")
            )
        );
        addHandler(el, 'change',
            "var $$a=" + value + "," +
            '$$el=$event.target,' +
            "$$c=$$el.checked?(" + trueValueBinding + "):(" + falseValueBinding + ");" +
            'if(Array.isArray($$a)){' +
            "var $$v=" + (number ? '_n(' + valueBinding + ')' : valueBinding) + "," +
            '$$i=_i($$a,$$v);' +
            "if($$el.checked){$$i<0&&(" + (genAssignmentCode(value, '$$a.concat([$$v])')) + ")}" +
            "else{$$i>-1&&(" + (genAssignmentCode(value, '$$a.slice(0,$$i).concat($$a.slice($$i+1))')) + ")}" +
            "}else{" + (genAssignmentCode(value, '$$c')) + "}",
            null, true
        );
    }

    function genRadioModel (
        el,
        value,
        modifiers
    ) {
        var number = modifiers && modifiers.number;
        var valueBinding = getBindingAttr(el, 'value') || 'null';
        valueBinding = number ? ("_n(" + valueBinding + ")") : valueBinding;
        addProp(el, 'checked', ("_q(" + value + "," + valueBinding + ")"));
        addHandler(el, 'change', genAssignmentCode(value, valueBinding), null, true);
    }

    function genSelect (
        el,
        value,
        modifiers
    ) {
        var number = modifiers && modifiers.number;
        var selectedVal = "Array.prototype.filter" +
            ".call($event.target.options,function(o){return o.selected})" +
            ".map(function(o){var val = \"_value\" in o ? o._value : o.value;" +
            "return " + (number ? '_n(val)' : 'val') + "})";

        var assignment = '$event.target.multiple ? $$selectedVal : $$selectedVal[0]';
        var code = "var $$selectedVal = " + selectedVal + ";";
        code = code + " " + (genAssignmentCode(value, assignment));
        addHandler(el, 'change', code, null, true);
    }

    function genDefaultModel (
        el,
        value,
        modifiers
    ) {
        var type = el.attrsMap.type;

        // warn if v-bind:value conflicts with v-model
        // except for inputs with v-bind:type
        {
            var value$1 = el.attrsMap['v-bind:value'] || el.attrsMap[':value'];
            var typeBinding = el.attrsMap['v-bind:type'] || el.attrsMap[':type'];
            if (value$1 && !typeBinding) {
                var binding = el.attrsMap['v-bind:value'] ? 'v-bind:value' : ':value';
                warn$1(
                    binding + "=\"" + value$1 + "\" conflicts with v-model on the same element " +
                    'because the latter already expands to a value binding internally',
                    el.rawAttrsMap[binding]
                );
            }
        }

        var ref = modifiers || {};
        var lazy = ref.lazy;
        var number = ref.number;
        var trim = ref.trim;
        var needCompositionGuard = !lazy && type !== 'range';
        var event = lazy
            ? 'change'
            : type === 'range'
            ? RANGE_TOKEN
            : 'input';

        var valueExpression = '$event.target.value';
        if (trim) {
            valueExpression = "$event.target.value.trim()";
        }
        if (number) {
            valueExpression = "_n(" + valueExpression + ")";
        }

        var code = genAssignmentCode(value, valueExpression);
        if (needCompositionGuard) {
            code = "if($event.target.composing)return;" + code;
        }

        addProp(el, 'value', ("(" + value + ")"));
        addHandler(el, event, code, null, true);
        if (trim || number) {
            addHandler(el, 'blur', '$forceUpdate()');
        }
    }

    /*  */

    // normalize v-model event tokens that can only be determined at runtime.
    // it's important to place the event as the first in the array because
    // the whole point is ensuring the v-model callback gets called before
    // user-attached handlers.
    function normalizeEvents (on) {
        /* istanbul ignore if */
        if (isDef(on[RANGE_TOKEN])) {
            // IE input[type=range] only supports `change` event
            var event = isIE ? 'change' : 'input';
            on[event] = [].concat(on[RANGE_TOKEN], on[event] || []);
            delete on[RANGE_TOKEN];
        }
        // This was originally intended to fix #4521 but no longer necessary
        // after 2.5. Keeping it for backwards compat with generated code from < 2.4
        /* istanbul ignore if */
        if (isDef(on[CHECKBOX_RADIO_TOKEN])) {
            on.change = [].concat(on[CHECKBOX_RADIO_TOKEN], on.change || []);
            delete on[CHECKBOX_RADIO_TOKEN];
        }
    }

    var target$1;

    function createOnceHandler$1 (event, handler, capture) {
        var _target = target$1; // save current target element in closure
        return function onceHandler () {
            var res = handler.apply(null, arguments);
            if (res !== null) {
                remove$2(event, onceHandler, capture, _target);
            }
        }
    }

    // #9446: Firefox <= 53 (in particular, ESR 52) has incorrect Event.timeStamp
    // implementation and does not fire microtasks in between event propagation, so
    // safe to exclude.
    var useMicrotaskFix = isUsingMicroTask && !(isFF && Number(isFF[1]) <= 53);

    function add$1 (
        name,
        handler,
        capture,
        passive
    ) {
        // async edge case #6566: inner click event triggers patch, event handler
        // attached to outer element during patch, and triggered again. This
        // happens because browsers fire microtask ticks between event propagation.
        // the solution is simple: we save the timestamp when a handler is attached,
        // and the handler would only fire if the event passed to it was fired
        // AFTER it was attached.
        if (useMicrotaskFix) {
            var attachedTimestamp = currentFlushTimestamp;
            var original = handler;
            handler = original._wrapper = function (e) {
                if (
                    // no bubbling, should always fire.
                // this is just a safety net in case event.timeStamp is unreliable in
                // certain weird environments...
                e.target === e.currentTarget ||
                    // event is fired after handler attachment
                e.timeStamp >= attachedTimestamp ||
                    // bail for environments that have buggy event.timeStamp implementations
                    // #9462 iOS 9 bug: event.timeStamp is 0 after history.pushState
                    // #9681 QtWebEngine event.timeStamp is negative value
                e.timeStamp <= 0 ||
                    // #9448 bail if event is fired in another document in a multi-page
                    // electron/nw.js app, since event.timeStamp will be using a different
                    // starting reference
                e.target.ownerDocument !== document
                ) {
                    return original.apply(this, arguments)
                }
            };
        }
        target$1.addEventListener(
            name,
            handler,
            supportsPassive
                ? { capture: capture, passive: passive }
                : capture
        );
    }

    function remove$2 (
        name,
        handler,
        capture,
        _target
    ) {
        (_target || target$1).removeEventListener(
            name,
            handler._wrapper || handler,
            capture
        );
    }

    function updateDOMListeners (oldVnode, vnode) {
        if (isUndef(oldVnode.data.on) && isUndef(vnode.data.on)) {
            return
        }
        var on = vnode.data.on || {};
        var oldOn = oldVnode.data.on || {};
        target$1 = vnode.elm;
        normalizeEvents(on);
        updateListeners(on, oldOn, add$1, remove$2, createOnceHandler$1, vnode.context);
        target$1 = undefined;
    }

    var events = {
        create: updateDOMListeners,
        update: updateDOMListeners
    };

    /*  */

    var svgContainer;

    function updateDOMProps (oldVnode, vnode) {
        if (isUndef(oldVnode.data.domProps) && isUndef(vnode.data.domProps)) {
            return
        }
        var key, cur;
        var elm = vnode.elm;
        var oldProps = oldVnode.data.domProps || {};
        var props = vnode.data.domProps || {};
        // clone observed objects, as the user probably wants to mutate it
        if (isDef(props.__ob__)) {
            props = vnode.data.domProps = extend({}, props);
        }

        for (key in oldProps) {
            if (!(key in props)) {
                elm[key] = '';
            }
        }

        for (key in props) {
            cur = props[key];
            // ignore children if the node has textContent or innerHTML,
            // as these will throw away existing DOM nodes and cause removal errors
            // on subsequent patches (#3360)
            if (key === 'textContent' || key === 'innerHTML') {
                if (vnode.children) { vnode.children.length = 0; }
                if (cur === oldProps[key]) { continue }
                // #6601 work around Chrome version <= 55 bug where single textNode
                // replaced by innerHTML/textContent retains its parentNode property
                if (elm.childNodes.length === 1) {
                    elm.removeChild(elm.childNodes[0]);
                }
            }

            if (key === 'value' && elm.tagName !== 'PROGRESS') {
                // store value as _value as well since
                // non-string values will be stringified
                elm._value = cur;
                // avoid resetting cursor position when value is the same
                var strCur = isUndef(cur) ? '' : String(cur);
                if (shouldUpdateValue(elm, strCur)) {
                    elm.value = strCur;
                }
            } else if (key === 'innerHTML' && isSVG(elm.tagName) && isUndef(elm.innerHTML)) {
                // IE doesn't support innerHTML for SVG elements
                svgContainer = svgContainer || document.createElement('div');
                svgContainer.innerHTML = "<svg>" + cur + "</svg>";
                var svg = svgContainer.firstChild;
                while (elm.firstChild) {
                    elm.removeChild(elm.firstChild);
                }
                while (svg.firstChild) {
                    elm.appendChild(svg.firstChild);
                }
            } else if (
                // skip the update if old and new VDOM state is the same.
            // `value` is handled separately because the DOM value may be temporarily
            // out of sync with VDOM state due to focus, composition and modifiers.
            // This  #4521 by skipping the unnecesarry `checked` update.
            cur !== oldProps[key]
            ) {
                // some property updates can throw
                // e.g. `value` on <progress> w/ non-finite value
                try {
                    elm[key] = cur;
                } catch (e) {}
            }
        }
    }

    // check platforms/web/util/attrs.js acceptValue


    function shouldUpdateValue (elm, checkVal) {
        return (!elm.composing && (
            elm.tagName === 'OPTION' ||
            isNotInFocusAndDirty(elm, checkVal) ||
            isDirtyWithModifiers(elm, checkVal)
        ))
    }

    function isNotInFocusAndDirty (elm, checkVal) {
        // return true when textbox (.number and .trim) loses focus and its value is
        // not equal to the updated value
        var notInFocus = true;
        // #6157
        // work around IE bug when accessing document.activeElement in an iframe
        try { notInFocus = document.activeElement !== elm; } catch (e) {}
        return notInFocus && elm.value !== checkVal
    }

    function isDirtyWithModifiers (elm, newVal) {
        var value = elm.value;
        var modifiers = elm._vModifiers; // injected by v-model runtime
        if (isDef(modifiers)) {
            if (modifiers.number) {
                return toNumber(value) !== toNumber(newVal)
            }
            if (modifiers.trim) {
                return value.trim() !== newVal.trim()
            }
        }
        return value !== newVal
    }

    var domProps = {
        create: updateDOMProps,
        update: updateDOMProps
    };

    /*  */

    var parseStyleText = cached(function (cssText) {
        var res = {};
        var listDelimiter = /;(?![^(]*\))/g;
        var propertyDelimiter = /:(.+)/;
        cssText.split(listDelimiter).forEach(function (item) {
            if (item) {
                var tmp = item.split(propertyDelimiter);
                tmp.length > 1 && (res[tmp[0].trim()] = tmp[1].trim());
            }
        });
        return res
    });

    // merge static and dynamic style data on the same vnode
    function normalizeStyleData (data) {
        var style = normalizeStyleBinding(data.style);
        // static style is pre-processed into an object during compilation
        // and is always a fresh object, so it's safe to merge into it
        return data.staticStyle
            ? extend(data.staticStyle, style)
            : style
    }

    // normalize possible array / string values into Object
    function normalizeStyleBinding (bindingStyle) {
        if (Array.isArray(bindingStyle)) {
            return toObject(bindingStyle)
        }
        if (typeof bindingStyle === 'string') {
            return parseStyleText(bindingStyle)
        }
        return bindingStyle
    }

    /**
     * parent component style should be after child's
     * so that parent component's style could override it
     */
    function getStyle (vnode, checkChild) {
        var res = {};
        var styleData;

        if (checkChild) {
            var childNode = vnode;
            while (childNode.componentInstance) {
                childNode = childNode.componentInstance._vnode;
                if (
                    childNode && childNode.data &&
                    (styleData = normalizeStyleData(childNode.data))
                ) {
                    extend(res, styleData);
                }
            }
        }

        if ((styleData = normalizeStyleData(vnode.data))) {
            extend(res, styleData);
        }

        var parentNode = vnode;
        while ((parentNode = parentNode.parent)) {
            if (parentNode.data && (styleData = normalizeStyleData(parentNode.data))) {
                extend(res, styleData);
            }
        }
        return res
    }

    /*  */

    var cssVarRE = /^--/;
    var importantRE = /\s*!important$/;
    var setProp = function (el, name, val) {
        /* istanbul ignore if */
        if (cssVarRE.test(name)) {
            el.style.setProperty(name, val);
        } else if (importantRE.test(val)) {
            el.style.setProperty(hyphenate(name), val.replace(importantRE, ''), 'important');
        } else {
            var normalizedName = normalize(name);
            if (Array.isArray(val)) {
                // Support values array created by autoprefixer, e.g.
                // {display: ["-webkit-box", "-ms-flexbox", "flex"]}
                // Set them one by one, and the browser will only set those it can recognize
                for (var i = 0, len = val.length; i < len; i++) {
                    el.style[normalizedName] = val[i];
                }
            } else {
                el.style[normalizedName] = val;
            }
        }
    };

    var vendorNames = ['Webkit', 'Moz', 'ms'];

    var emptyStyle;
    var normalize = cached(function (prop) {
        emptyStyle = emptyStyle || document.createElement('div').style;
        prop = camelize(prop);
        if (prop !== 'filter' && (prop in emptyStyle)) {
            return prop
        }
        var capName = prop.charAt(0).toUpperCase() + prop.slice(1);
        for (var i = 0; i < vendorNames.length; i++) {
            var name = vendorNames[i] + capName;
            if (name in emptyStyle) {
                return name
            }
        }
    });

    function updateStyle (oldVnode, vnode) {
        var data = vnode.data;
        var oldData = oldVnode.data;

        if (isUndef(data.staticStyle) && isUndef(data.style) &&
            isUndef(oldData.staticStyle) && isUndef(oldData.style)
        ) {
            return
        }

        var cur, name;
        var el = vnode.elm;
        var oldStaticStyle = oldData.staticStyle;
        var oldStyleBinding = oldData.normalizedStyle || oldData.style || {};

        // if static style exists, stylebinding already merged into it when doing normalizeStyleData
        var oldStyle = oldStaticStyle || oldStyleBinding;

        var style = normalizeStyleBinding(vnode.data.style) || {};

        // store normalized style under a different key for next diff
        // make sure to clone it if it's reactive, since the user likely wants
        // to mutate it.
        vnode.data.normalizedStyle = isDef(style.__ob__)
            ? extend({}, style)
            : style;

        var newStyle = getStyle(vnode, true);

        for (name in oldStyle) {
            if (isUndef(newStyle[name])) {
                setProp(el, name, '');
            }
        }
        for (name in newStyle) {
            cur = newStyle[name];
            if (cur !== oldStyle[name]) {
                // ie9 setting to null has no effect, must use empty string
                setProp(el, name, cur == null ? '' : cur);
            }
        }
    }

    var style = {
        create: updateStyle,
        update: updateStyle
    };

    /*  */

    var whitespaceRE = /\s+/;

    /**
     * Add class with compatibility for SVG since classList is not supported on
     * SVG elements in IE
     */
    function addClass (el, cls) {
        /* istanbul ignore if */
        if (!cls || !(cls = cls.trim())) {
            return
        }

        /* istanbul ignore else */
        if (el.classList) {
            if (cls.indexOf(' ') > -1) {
                cls.split(whitespaceRE).forEach(function (c) { return el.classList.add(c); });
            } else {
                el.classList.add(cls);
            }
        } else {
            var cur = " " + (el.getAttribute('class') || '') + " ";
            if (cur.indexOf(' ' + cls + ' ') < 0) {
                el.setAttribute('class', (cur + cls).trim());
            }
        }
    }

    /**
     * Remove class with compatibility for SVG since classList is not supported on
     * SVG elements in IE
     */
    function removeClass (el, cls) {
        /* istanbul ignore if */
        if (!cls || !(cls = cls.trim())) {
            return
        }

        /* istanbul ignore else */
        if (el.classList) {
            if (cls.indexOf(' ') > -1) {
                cls.split(whitespaceRE).forEach(function (c) { return el.classList.remove(c); });
            } else {
                el.classList.remove(cls);
            }
            if (!el.classList.length) {
                el.removeAttribute('class');
            }
        } else {
            var cur = " " + (el.getAttribute('class') || '') + " ";
            var tar = ' ' + cls + ' ';
            while (cur.indexOf(tar) >= 0) {
                cur = cur.replace(tar, ' ');
            }
            cur = cur.trim();
            if (cur) {
                el.setAttribute('class', cur);
            } else {
                el.removeAttribute('class');
            }
        }
    }

    /*  */

    function resolveTransition (def$$1) {
        if (!def$$1) {
            return
        }
        /* istanbul ignore else */
        if (typeof def$$1 === 'object') {
            var res = {};
            if (def$$1.css !== false) {
                extend(res, autoCssTransition(def$$1.name || 'v'));
            }
            extend(res, def$$1);
            return res
        } else if (typeof def$$1 === 'string') {
            return autoCssTransition(def$$1)
        }
    }

    var autoCssTransition = cached(function (name) {
        return {
            enterClass: (name + "-enter"),
            enterToClass: (name + "-enter-to"),
            enterActiveClass: (name + "-enter-active"),
            leaveClass: (name + "-leave"),
            leaveToClass: (name + "-leave-to"),
            leaveActiveClass: (name + "-leave-active")
        }
    });

    var hasTransition = inBrowser && !isIE9;
    var TRANSITION = 'transition';
    var ANIMATION = 'animation';

    // Transition property/event sniffing
    var transitionProp = 'transition';
    var transitionEndEvent = 'transitionend';
    var animationProp = 'animation';
    var animationEndEvent = 'animationend';
    if (hasTransition) {
        /* istanbul ignore if */
        if (window.ontransitionend === undefined &&
            window.onwebkittransitionend !== undefined
        ) {
            transitionProp = 'WebkitTransition';
            transitionEndEvent = 'webkitTransitionEnd';
        }
        if (window.onanimationend === undefined &&
            window.onwebkitanimationend !== undefined
        ) {
            animationProp = 'WebkitAnimation';
            animationEndEvent = 'webkitAnimationEnd';
        }
    }

    // binding to window is necessary to make hot reload work in IE in strict mode
    var raf = inBrowser
        ? window.requestAnimationFrame
        ? window.requestAnimationFrame.bind(window)
        : setTimeout
        : /* istanbul ignore next */ function (fn) { return fn(); };

    function nextFrame (fn) {
        raf(function () {
            raf(fn);
        });
    }

    function addTransitionClass (el, cls) {
        var transitionClasses = el._transitionClasses || (el._transitionClasses = []);
        if (transitionClasses.indexOf(cls) < 0) {
            transitionClasses.push(cls);
            addClass(el, cls);
        }
    }

    function removeTransitionClass (el, cls) {
        if (el._transitionClasses) {
            remove(el._transitionClasses, cls);
        }
        removeClass(el, cls);
    }

    function whenTransitionEnds (
        el,
        expectedType,
        cb
    ) {
        var ref = getTransitionInfo(el, expectedType);
        var type = ref.type;
        var timeout = ref.timeout;
        var propCount = ref.propCount;
        if (!type) { return cb() }
        var event = type === TRANSITION ? transitionEndEvent : animationEndEvent;
        var ended = 0;
        var end = function () {
            el.removeEventListener(event, onEnd);
            cb();
        };
        var onEnd = function (e) {
            if (e.target === el) {
                if (++ended >= propCount) {
                    end();
                }
            }
        };
        setTimeout(function () {
            if (ended < propCount) {
                end();
            }
        }, timeout + 1);
        el.addEventListener(event, onEnd);
    }

    var transformRE = /\b(transform|all)(,|$)/;

    function getTransitionInfo (el, expectedType) {
        var styles = window.getComputedStyle(el);
        // JSDOM may return undefined for transition properties
        var transitionDelays = (styles[transitionProp + 'Delay'] || '').split(', ');
        var transitionDurations = (styles[transitionProp + 'Duration'] || '').split(', ');
        var transitionTimeout = getTimeout(transitionDelays, transitionDurations);
        var animationDelays = (styles[animationProp + 'Delay'] || '').split(', ');
        var animationDurations = (styles[animationProp + 'Duration'] || '').split(', ');
        var animationTimeout = getTimeout(animationDelays, animationDurations);

        var type;
        var timeout = 0;
        var propCount = 0;
        /* istanbul ignore if */
        if (expectedType === TRANSITION) {
            if (transitionTimeout > 0) {
                type = TRANSITION;
                timeout = transitionTimeout;
                propCount = transitionDurations.length;
            }
        } else if (expectedType === ANIMATION) {
            if (animationTimeout > 0) {
                type = ANIMATION;
                timeout = animationTimeout;
                propCount = animationDurations.length;
            }
        } else {
            timeout = Math.max(transitionTimeout, animationTimeout);
            type = timeout > 0
                ? transitionTimeout > animationTimeout
                ? TRANSITION
                : ANIMATION
                : null;
            propCount = type
                ? type === TRANSITION
                ? transitionDurations.length
                : animationDurations.length
                : 0;
        }
        var hasTransform =
            type === TRANSITION &&
            transformRE.test(styles[transitionProp + 'Property']);
        return {
            type: type,
            timeout: timeout,
            propCount: propCount,
            hasTransform: hasTransform
        }
    }

    function getTimeout (delays, durations) {
        /* istanbul ignore next */
        while (delays.length < durations.length) {
            delays = delays.concat(delays);
        }

        return Math.max.apply(null, durations.map(function (d, i) {
            return toMs(d) + toMs(delays[i])
        }))
    }

    // Old versions of Chromium (below 61.0.3163.100) formats floating pointer numbers
    // in a locale-dependent way, using a comma instead of a dot.
    // If comma is not replaced with a dot, the input will be rounded down (i.e. acting
    // as a floor function) causing unexpected behaviors
    function toMs (s) {
        return Number(s.slice(0, -1).replace(',', '.')) * 1000
    }

    /*  */

    function enter (vnode, toggleDisplay) {
        var el = vnode.elm;

        // call leave callback now
        if (isDef(el._leaveCb)) {
            el._leaveCb.cancelled = true;
            el._leaveCb();
        }

        var data = resolveTransition(vnode.data.transition);
        if (isUndef(data)) {
            return
        }

        /* istanbul ignore if */
        if (isDef(el._enterCb) || el.nodeType !== 1) {
            return
        }

        var css = data.css;
        var type = data.type;
        var enterClass = data.enterClass;
        var enterToClass = data.enterToClass;
        var enterActiveClass = data.enterActiveClass;
        var appearClass = data.appearClass;
        var appearToClass = data.appearToClass;
        var appearActiveClass = data.appearActiveClass;
        var beforeEnter = data.beforeEnter;
        var enter = data.enter;
        var afterEnter = data.afterEnter;
        var enterCancelled = data.enterCancelled;
        var beforeAppear = data.beforeAppear;
        var appear = data.appear;
        var afterAppear = data.afterAppear;
        var appearCancelled = data.appearCancelled;
        var duration = data.duration;

        // activeInstance will always be the <transition> component managing this
        // transition. One edge case to check is when the <transition> is placed
        // as the root node of a child component. In that case we need to check
        // <transition>'s parent for appear check.
        var context = activeInstance;
        var transitionNode = activeInstance.$vnode;
        while (transitionNode && transitionNode.parent) {
            context = transitionNode.context;
            transitionNode = transitionNode.parent;
        }

        var isAppear = !context._isMounted || !vnode.isRootInsert;

        if (isAppear && !appear && appear !== '') {
            return
        }

        var startClass = isAppear && appearClass
            ? appearClass
            : enterClass;
        var activeClass = isAppear && appearActiveClass
            ? appearActiveClass
            : enterActiveClass;
        var toClass = isAppear && appearToClass
            ? appearToClass
            : enterToClass;

        var beforeEnterHook = isAppear
            ? (beforeAppear || beforeEnter)
            : beforeEnter;
        var enterHook = isAppear
            ? (typeof appear === 'function' ? appear : enter)
            : enter;
        var afterEnterHook = isAppear
            ? (afterAppear || afterEnter)
            : afterEnter;
        var enterCancelledHook = isAppear
            ? (appearCancelled || enterCancelled)
            : enterCancelled;

        var explicitEnterDuration = toNumber(
            isObject(duration)
                ? duration.enter
                : duration
        );

        if (explicitEnterDuration != null) {
            checkDuration(explicitEnterDuration, 'enter', vnode);
        }

        var expectsCSS = css !== false && !isIE9;
        var userWantsControl = getHookArgumentsLength(enterHook);

        var cb = el._enterCb = once(function () {
            if (expectsCSS) {
                removeTransitionClass(el, toClass);
                removeTransitionClass(el, activeClass);
            }
            if (cb.cancelled) {
                if (expectsCSS) {
                    removeTransitionClass(el, startClass);
                }
                enterCancelledHook && enterCancelledHook(el);
            } else {
                afterEnterHook && afterEnterHook(el);
            }
            el._enterCb = null;
        });

        if (!vnode.data.show) {
            // remove pending leave element on enter by injecting an insert hook
            mergeVNodeHook(vnode, 'insert', function () {
                var parent = el.parentNode;
                var pendingNode = parent && parent._pending && parent._pending[vnode.key];
                if (pendingNode &&
                    pendingNode.tag === vnode.tag &&
                    pendingNode.elm._leaveCb
                ) {
                    pendingNode.elm._leaveCb();
                }
                enterHook && enterHook(el, cb);
            });
        }

        // start enter transition
        beforeEnterHook && beforeEnterHook(el);
        if (expectsCSS) {
            addTransitionClass(el, startClass);
            addTransitionClass(el, activeClass);
            nextFrame(function () {
                removeTransitionClass(el, startClass);
                if (!cb.cancelled) {
                    addTransitionClass(el, toClass);
                    if (!userWantsControl) {
                        if (isValidDuration(explicitEnterDuration)) {
                            setTimeout(cb, explicitEnterDuration);
                        } else {
                            whenTransitionEnds(el, type, cb);
                        }
                    }
                }
            });
        }

        if (vnode.data.show) {
            toggleDisplay && toggleDisplay();
            enterHook && enterHook(el, cb);
        }

        if (!expectsCSS && !userWantsControl) {
            cb();
        }
    }

    function leave (vnode, rm) {
        var el = vnode.elm;

        // call enter callback now
        if (isDef(el._enterCb)) {
            el._enterCb.cancelled = true;
            el._enterCb();
        }

        var data = resolveTransition(vnode.data.transition);
        if (isUndef(data) || el.nodeType !== 1) {
            return rm()
        }

        /* istanbul ignore if */
        if (isDef(el._leaveCb)) {
            return
        }

        var css = data.css;
        var type = data.type;
        var leaveClass = data.leaveClass;
        var leaveToClass = data.leaveToClass;
        var leaveActiveClass = data.leaveActiveClass;
        var beforeLeave = data.beforeLeave;
        var leave = data.leave;
        var afterLeave = data.afterLeave;
        var leaveCancelled = data.leaveCancelled;
        var delayLeave = data.delayLeave;
        var duration = data.duration;

        var expectsCSS = css !== false && !isIE9;
        var userWantsControl = getHookArgumentsLength(leave);

        var explicitLeaveDuration = toNumber(
            isObject(duration)
                ? duration.leave
                : duration
        );

        if (isDef(explicitLeaveDuration)) {
            checkDuration(explicitLeaveDuration, 'leave', vnode);
        }

        var cb = el._leaveCb = once(function () {
            if (el.parentNode && el.parentNode._pending) {
                el.parentNode._pending[vnode.key] = null;
            }
            if (expectsCSS) {
                removeTransitionClass(el, leaveToClass);
                removeTransitionClass(el, leaveActiveClass);
            }
            if (cb.cancelled) {
                if (expectsCSS) {
                    removeTransitionClass(el, leaveClass);
                }
                leaveCancelled && leaveCancelled(el);
            } else {
                rm();
                afterLeave && afterLeave(el);
            }
            el._leaveCb = null;
        });

        if (delayLeave) {
            delayLeave(performLeave);
        } else {
            performLeave();
        }

        function performLeave () {
            // the delayed leave may have already been cancelled
            if (cb.cancelled) {
                return
            }
            // record leaving element
            if (!vnode.data.show && el.parentNode) {
                (el.parentNode._pending || (el.parentNode._pending = {}))[(vnode.key)] = vnode;
            }
            beforeLeave && beforeLeave(el);
            if (expectsCSS) {
                addTransitionClass(el, leaveClass);
                addTransitionClass(el, leaveActiveClass);
                nextFrame(function () {
                    removeTransitionClass(el, leaveClass);
                    if (!cb.cancelled) {
                        addTransitionClass(el, leaveToClass);
                        if (!userWantsControl) {
                            if (isValidDuration(explicitLeaveDuration)) {
                                setTimeout(cb, explicitLeaveDuration);
                            } else {
                                whenTransitionEnds(el, type, cb);
                            }
                        }
                    }
                });
            }
            leave && leave(el, cb);
            if (!expectsCSS && !userWantsControl) {
                cb();
            }
        }
    }

    // only used in dev mode
    function checkDuration (val, name, vnode) {
        if (typeof val !== 'number') {
            warn(
                "<transition> explicit " + name + " duration is not a valid number - " +
                "got " + (JSON.stringify(val)) + ".",
                vnode.context
            );
        } else if (isNaN(val)) {
            warn(
                "<transition> explicit " + name + " duration is NaN - " +
                'the duration expression might be incorrect.',
                vnode.context
            );
        }
    }

    function isValidDuration (val) {
        return typeof val === 'number' && !isNaN(val)
    }

    /**
     * Normalize a transition hook's argument length. The hook may be:
     * - a merged hook (invoker) with the original in .fns
     * - a wrapped component method (check ._length)
     * - a plain function (.length)
     */
    function getHookArgumentsLength (fn) {
        if (isUndef(fn)) {
            return false
        }
        var invokerFns = fn.fns;
        if (isDef(invokerFns)) {
            // invoker
            return getHookArgumentsLength(
                Array.isArray(invokerFns)
                    ? invokerFns[0]
                    : invokerFns
            )
        } else {
            return (fn._length || fn.length) > 1
        }
    }

    function _enter (_, vnode) {
        if (vnode.data.show !== true) {
            enter(vnode);
        }
    }

    var transition = inBrowser ? {
        create: _enter,
        activate: _enter,
        remove: function remove$$1 (vnode, rm) {
            /* istanbul ignore else */
            if (vnode.data.show !== true) {
                leave(vnode, rm);
            } else {
                rm();
            }
        }
    } : {};

    var platformModules = [
        attrs,
        klass,
        events,
        domProps,
        style,
        transition
    ];

    /*  */

    // the directive module should be applied last, after all
    // built-in modules have been applied.
    var modules = platformModules.concat(baseModules);

    var patch = createPatchFunction({ nodeOps: nodeOps, modules: modules });

    /**
     * Not type checking this file because flow doesn't like attaching
     * properties to Elements.
     */

    /* istanbul ignore if */
    if (isIE9) {
        // http://www.matts411.com/post/internet-explorer-9-oninput/
        document.addEventListener('selectionchange', function () {
            var el = document.activeElement;
            if (el && el.vmodel) {
                trigger(el, 'input');
            }
        });
    }

    var directive = {
        inserted: function inserted (el, binding, vnode, oldVnode) {
            if (vnode.tag === 'select') {
                // #6903
                if (oldVnode.elm && !oldVnode.elm._vOptions) {
                    mergeVNodeHook(vnode, 'postpatch', function () {
                        directive.componentUpdated(el, binding, vnode);
                    });
                } else {
                    setSelected(el, binding, vnode.context);
                }
                el._vOptions = [].map.call(el.options, getValue);
            } else if (vnode.tag === 'textarea' || isTextInputType(el.type)) {
                el._vModifiers = binding.modifiers;
                if (!binding.modifiers.lazy) {
                    el.addEventListener('compositionstart', onCompositionStart);
                    el.addEventListener('compositionend', onCompositionEnd);
                    // Safari < 10.2 & UIWebView doesn't fire compositionend when
                    // switching focus before confirming composition choice
                    // this also fixes the issue where some browsers e.g. iOS Chrome
                    // fires "change" instead of "input" on autocomplete.
                    el.addEventListener('change', onCompositionEnd);
                    /* istanbul ignore if */
                    if (isIE9) {
                        el.vmodel = true;
                    }
                }
            }
        },

        componentUpdated: function componentUpdated (el, binding, vnode) {
            if (vnode.tag === 'select') {
                setSelected(el, binding, vnode.context);
                // in case the options rendered by v-for have changed,
                // it's possible that the value is out-of-sync with the rendered options.
                // detect such cases and filter out values that no longer has a matching
                // option in the DOM.
                var prevOptions = el._vOptions;
                var curOptions = el._vOptions = [].map.call(el.options, getValue);
                if (curOptions.some(function (o, i) { return !looseEqual(o, prevOptions[i]); })) {
                    // trigger change event if
                    // no matching option found for at least one value
                    var needReset = el.multiple
                        ? binding.value.some(function (v) { return hasNoMatchingOption(v, curOptions); })
                        : binding.value !== binding.oldValue && hasNoMatchingOption(binding.value, curOptions);
                    if (needReset) {
                        trigger(el, 'change');
                    }
                }
            }
        }
    };

    function setSelected (el, binding, vm) {
        actuallySetSelected(el, binding, vm);
        /* istanbul ignore if */
        if (isIE || isEdge) {
            setTimeout(function () {
                actuallySetSelected(el, binding, vm);
            }, 0);
        }
    }

    function actuallySetSelected (el, binding, vm) {
        var value = binding.value;
        var isMultiple = el.multiple;
        if (isMultiple && !Array.isArray(value)) {
            warn(
                "<select multiple v-model=\"" + (binding.expression) + "\"> " +
                "expects an Array value for its binding, but got " + (Object.prototype.toString.call(value).slice(8, -1)),
                vm
            );
            return
        }
        var selected, option;
        for (var i = 0, l = el.options.length; i < l; i++) {
            option = el.options[i];
            if (isMultiple) {
                selected = looseIndexOf(value, getValue(option)) > -1;
                if (option.selected !== selected) {
                    option.selected = selected;
                }
            } else {
                if (looseEqual(getValue(option), value)) {
                    if (el.selectedIndex !== i) {
                        el.selectedIndex = i;
                    }
                    return
                }
            }
        }
        if (!isMultiple) {
            el.selectedIndex = -1;
        }
    }

    function hasNoMatchingOption (value, options) {
        return options.every(function (o) { return !looseEqual(o, value); })
    }

    function getValue (option) {
        return '_value' in option
            ? option._value
            : option.value
    }

    function onCompositionStart (e) {
        e.target.composing = true;
    }

    function onCompositionEnd (e) {
        // prevent triggering an input event for no reason
        if (!e.target.composing) { return }
        e.target.composing = false;
        trigger(e.target, 'input');
    }

    function trigger (el, type) {
        var e = document.createEvent('HTMLEvents');
        e.initEvent(type, true, true);
        el.dispatchEvent(e);
    }

    /*  */

    // recursively search for possible transition defined inside the component root
    function locateNode (vnode) {
        return vnode.componentInstance && (!vnode.data || !vnode.data.transition)
            ? locateNode(vnode.componentInstance._vnode)
            : vnode
    }

    var show = {
        bind: function bind (el, ref, vnode) {
            var value = ref.value;

            vnode = locateNode(vnode);
            var transition$$1 = vnode.data && vnode.data.transition;
            var originalDisplay = el.__vOriginalDisplay =
                el.style.display === 'none' ? '' : el.style.display;
            if (value && transition$$1) {
                vnode.data.show = true;
                enter(vnode, function () {
                    el.style.display = originalDisplay;
                });
            } else {
                el.style.display = value ? originalDisplay : 'none';
            }
        },

        update: function update (el, ref, vnode) {
            var value = ref.value;
            var oldValue = ref.oldValue;

            /* istanbul ignore if */
            if (!value === !oldValue) { return }
            vnode = locateNode(vnode);
            var transition$$1 = vnode.data && vnode.data.transition;
            if (transition$$1) {
                vnode.data.show = true;
                if (value) {
                    enter(vnode, function () {
                        el.style.display = el.__vOriginalDisplay;
                    });
                } else {
                    leave(vnode, function () {
                        el.style.display = 'none';
                    });
                }
            } else {
                el.style.display = value ? el.__vOriginalDisplay : 'none';
            }
        },

        unbind: function unbind (
            el,
            binding,
            vnode,
            oldVnode,
            isDestroy
        ) {
            if (!isDestroy) {
                el.style.display = el.__vOriginalDisplay;
            }
        }
    };

    var platformDirectives = {
        model: directive,
        show: show
    };

    /*  */

    var transitionProps = {
        name: String,
        appear: Boolean,
        css: Boolean,
        mode: String,
        type: String,
        enterClass: String,
        leaveClass: String,
        enterToClass: String,
        leaveToClass: String,
        enterActiveClass: String,
        leaveActiveClass: String,
        appearClass: String,
        appearActiveClass: String,
        appearToClass: String,
        duration: [Number, String, Object]
    };

    // in case the child is also an abstract component, e.g. <keep-alive>
    // we want to recursively retrieve the real component to be rendered
    function getRealChild (vnode) {
        var compOptions = vnode && vnode.componentOptions;
        if (compOptions && compOptions.Ctor.options.abstract) {
            return getRealChild(getFirstComponentChild(compOptions.children))
        } else {
            return vnode
        }
    }

    function extractTransitionData (comp) {
        var data = {};
        var options = comp.$options;
        // props
        for (var key in options.propsData) {
            data[key] = comp[key];
        }
        // events.
        // extract listeners and pass them directly to the transition methods
        var listeners = options._parentListeners;
        for (var key$1 in listeners) {
            data[camelize(key$1)] = listeners[key$1];
        }
        return data
    }

    function placeholder (h, rawChild) {
        if (/\d-keep-alive$/.test(rawChild.tag)) {
            return h('keep-alive', {
                props: rawChild.componentOptions.propsData
            })
        }
    }

    function hasParentTransition (vnode) {
        while ((vnode = vnode.parent)) {
            if (vnode.data.transition) {
                return true
            }
        }
    }

    function isSameChild (child, oldChild) {
        return oldChild.key === child.key && oldChild.tag === child.tag
    }

    var isNotTextNode = function (c) { return c.tag || isAsyncPlaceholder(c); };

    var isVShowDirective = function (d) { return d.name === 'show'; };

    var Transition = {
        name: 'transition',
        props: transitionProps,
        abstract: true,

        render: function render (h) {
            var this$1 = this;

            var children = this.$slots.default;
            if (!children) {
                return
            }

            // filter out text nodes (possible whitespaces)
            children = children.filter(isNotTextNode);
            /* istanbul ignore if */
            if (!children.length) {
                return
            }

            // warn multiple elements
            if (children.length > 1) {
                warn(
                    '<transition> can only be used on a single element. Use ' +
                    '<transition-group> for lists.',
                    this.$parent
                );
            }

            var mode = this.mode;

            // warn invalid mode
            if (mode && mode !== 'in-out' && mode !== 'out-in'
            ) {
                warn(
                    'invalid <transition> mode: ' + mode,
                    this.$parent
                );
            }

            var rawChild = children[0];

            // if this is a component root node and the component's
            // parent container node also has transition, skip.
            if (hasParentTransition(this.$vnode)) {
                return rawChild
            }

            // apply transition data to child
            // use getRealChild() to ignore abstract components e.g. keep-alive
            var child = getRealChild(rawChild);
            /* istanbul ignore if */
            if (!child) {
                return rawChild
            }

            if (this._leaving) {
                return placeholder(h, rawChild)
            }

            // ensure a key that is unique to the vnode type and to this transition
            // component instance. This key will be used to remove pending leaving nodes
            // during entering.
            var id = "__transition-" + (this._uid) + "-";
            child.key = child.key == null
                ? child.isComment
                ? id + 'comment'
                : id + child.tag
                : isPrimitive(child.key)
                ? (String(child.key).indexOf(id) === 0 ? child.key : id + child.key)
                : child.key;

            var data = (child.data || (child.data = {})).transition = extractTransitionData(this);
            var oldRawChild = this._vnode;
            var oldChild = getRealChild(oldRawChild);

            // mark v-show
            // so that the transition module can hand over the control to the directive
            if (child.data.directives && child.data.directives.some(isVShowDirective)) {
                child.data.show = true;
            }

            if (
                oldChild &&
                oldChild.data &&
                !isSameChild(child, oldChild) &&
                !isAsyncPlaceholder(oldChild) &&
                    // #6687 component root is a comment node
                !(oldChild.componentInstance && oldChild.componentInstance._vnode.isComment)
            ) {
                // replace old child transition data with fresh one
                // important for dynamic transitions!
                var oldData = oldChild.data.transition = extend({}, data);
                // handle transition mode
                if (mode === 'out-in') {
                    // return placeholder node and queue update when leave finishes
                    this._leaving = true;
                    mergeVNodeHook(oldData, 'afterLeave', function () {
                        this$1._leaving = false;
                        this$1.$forceUpdate();
                    });
                    return placeholder(h, rawChild)
                } else if (mode === 'in-out') {
                    if (isAsyncPlaceholder(child)) {
                        return oldRawChild
                    }
                    var delayedLeave;
                    var performLeave = function () { delayedLeave(); };
                    mergeVNodeHook(data, 'afterEnter', performLeave);
                    mergeVNodeHook(data, 'enterCancelled', performLeave);
                    mergeVNodeHook(oldData, 'delayLeave', function (leave) { delayedLeave = leave; });
                }
            }

            return rawChild
        }
    };

    /*  */

    var props = extend({
        tag: String,
        moveClass: String
    }, transitionProps);

    delete props.mode;

    var TransitionGroup = {
        props: props,

        beforeMount: function beforeMount () {
            var this$1 = this;

            var update = this._update;
            this._update = function (vnode, hydrating) {
                var restoreActiveInstance = setActiveInstance(this$1);
                // force removing pass
                this$1.__patch__(
                    this$1._vnode,
                    this$1.kept,
                    false, // hydrating
                    true // removeOnly (!important, avoids unnecessary moves)
                );
                this$1._vnode = this$1.kept;
                restoreActiveInstance();
                update.call(this$1, vnode, hydrating);
            };
        },

        render: function render (h) {
            var tag = this.tag || this.$vnode.data.tag || 'span';
            var map = Object.create(null);
            var prevChildren = this.prevChildren = this.children;
            var rawChildren = this.$slots.default || [];
            var children = this.children = [];
            var transitionData = extractTransitionData(this);

            for (var i = 0; i < rawChildren.length; i++) {
                var c = rawChildren[i];
                if (c.tag) {
                    if (c.key != null && String(c.key).indexOf('__vlist') !== 0) {
                        children.push(c);
                        map[c.key] = c
                        ;(c.data || (c.data = {})).transition = transitionData;
                    } else {
                        var opts = c.componentOptions;
                        var name = opts ? (opts.Ctor.options.name || opts.tag || '') : c.tag;
                        warn(("<transition-group> children must be keyed: <" + name + ">"));
                    }
                }
            }

            if (prevChildren) {
                var kept = [];
                var removed = [];
                for (var i$1 = 0; i$1 < prevChildren.length; i$1++) {
                    var c$1 = prevChildren[i$1];
                    c$1.data.transition = transitionData;
                    c$1.data.pos = c$1.elm.getBoundingClientRect();
                    if (map[c$1.key]) {
                        kept.push(c$1);
                    } else {
                        removed.push(c$1);
                    }
                }
                this.kept = h(tag, null, kept);
                this.removed = removed;
            }

            return h(tag, null, children)
        },

        updated: function updated () {
            var children = this.prevChildren;
            var moveClass = this.moveClass || ((this.name || 'v') + '-move');
            if (!children.length || !this.hasMove(children[0].elm, moveClass)) {
                return
            }

            // we divide the work into three loops to avoid mixing DOM reads and writes
            // in each iteration - which helps prevent layout thrashing.
            children.forEach(callPendingCbs);
            children.forEach(recordPosition);
            children.forEach(applyTranslation);

            // force reflow to put everything in position
            // assign to this to avoid being removed in tree-shaking
            // $flow-disable-line
            this._reflow = document.body.offsetHeight;

            children.forEach(function (c) {
                if (c.data.moved) {
                    var el = c.elm;
                    var s = el.style;
                    addTransitionClass(el, moveClass);
                    s.transform = s.WebkitTransform = s.transitionDuration = '';
                    el.addEventListener(transitionEndEvent, el._moveCb = function cb (e) {
                        if (e && e.target !== el) {
                            return
                        }
                        if (!e || /transform$/.test(e.propertyName)) {
                            el.removeEventListener(transitionEndEvent, cb);
                            el._moveCb = null;
                            removeTransitionClass(el, moveClass);
                        }
                    });
                }
            });
        },

        methods: {
            hasMove: function hasMove (el, moveClass) {
                /* istanbul ignore if */
                if (!hasTransition) {
                    return false
                }
                /* istanbul ignore if */
                if (this._hasMove) {
                    return this._hasMove
                }
                // Detect whether an element with the move class applied has
                // CSS transitions. Since the element may be inside an entering
                // transition at this very moment, we make a clone of it and remove
                // all other transition classes applied to ensure only the move class
                // is applied.
                var clone = el.cloneNode();
                if (el._transitionClasses) {
                    el._transitionClasses.forEach(function (cls) { removeClass(clone, cls); });
                }
                addClass(clone, moveClass);
                clone.style.display = 'none';
                this.$el.appendChild(clone);
                var info = getTransitionInfo(clone);
                this.$el.removeChild(clone);
                return (this._hasMove = info.hasTransform)
            }
        }
    };

    function callPendingCbs (c) {
        /* istanbul ignore if */
        if (c.elm._moveCb) {
            c.elm._moveCb();
        }
        /* istanbul ignore if */
        if (c.elm._enterCb) {
            c.elm._enterCb();
        }
    }

    function recordPosition (c) {
        c.data.newPos = c.elm.getBoundingClientRect();
    }

    function applyTranslation (c) {
        var oldPos = c.data.pos;
        var newPos = c.data.newPos;
        var dx = oldPos.left - newPos.left;
        var dy = oldPos.top - newPos.top;
        if (dx || dy) {
            c.data.moved = true;
            var s = c.elm.style;
            s.transform = s.WebkitTransform = "translate(" + dx + "px," + dy + "px)";
            s.transitionDuration = '0s';
        }
    }

    var platformComponents = {
        Transition: Transition,
        TransitionGroup: TransitionGroup
    };

    /*  */

    // install platform specific utils
    Vue.config.mustUseProp = mustUseProp;
    Vue.config.isReservedTag = isReservedTag;
    Vue.config.isReservedAttr = isReservedAttr;
    Vue.config.getTagNamespace = getTagNamespace;
    Vue.config.isUnknownElement = isUnknownElement;

    // install platform runtime directives & components
    extend(Vue.options.directives, platformDirectives);
    extend(Vue.options.components, platformComponents);

    // install platform patch function
    Vue.prototype.__patch__ = inBrowser ? patch : noop;

    // public mount method
    Vue.prototype.$mount = function (
        el,
        hydrating
    ) {
        el = el && inBrowser ? query(el) : undefined;
        return mountComponent(this, el, hydrating)
    };

    // devtools global hook
    /* istanbul ignore next */
    if (inBrowser) {
        setTimeout(function () {
            if (config.devtools) {
                if (devtools) {
                    devtools.emit('init', Vue);
                } else {
                    console[console.info ? 'info' : 'log'](
                        'Download the Vue Devtools extension for a better development experience:\n' +
                        'https://github.com/vuejs/vue-devtools'
                    );
                }
            }
            if (config.productionTip !== false &&
                typeof console !== 'undefined'
            ) {
                console[console.info ? 'info' : 'log'](
                    "You are running Vue in development mode.\n" +
                    "Make sure to turn on production mode when deploying for production.\n" +
                    "See more tips at https://vuejs.org/guide/deployment.html"
                );
            }
        }, 0);
    }

    /*  */

    var defaultTagRE = /\{\{((?:.|\r?\n)+?)\}\}/g;
    var regexEscapeRE = /[-.*+?^${}()|[\]\/\\]/g;

    var buildRegex = cached(function (delimiters) {
        var open = delimiters[0].replace(regexEscapeRE, '\\$&');
        var close = delimiters[1].replace(regexEscapeRE, '\\$&');
        return new RegExp(open + '((?:.|\\n)+?)' + close, 'g')
    });



    function parseText (
        text,
        delimiters
    ) {
        var tagRE = delimiters ? buildRegex(delimiters) : defaultTagRE;
        if (!tagRE.test(text)) {
            return
        }
        var tokens = [];
        var rawTokens = [];
        var lastIndex = tagRE.lastIndex = 0;
        var match, index, tokenValue;
        while ((match = tagRE.exec(text))) {
            index = match.index;
            // push text token
            if (index > lastIndex) {
                rawTokens.push(tokenValue = text.slice(lastIndex, index));
                tokens.push(JSON.stringify(tokenValue));
            }
            // tag token
            var exp = parseFilters(match[1].trim());
            tokens.push(("_s(" + exp + ")"));
            rawTokens.push({ '@binding': exp });
            lastIndex = index + match[0].length;
        }
        if (lastIndex < text.length) {
            rawTokens.push(tokenValue = text.slice(lastIndex));
            tokens.push(JSON.stringify(tokenValue));
        }
        return {
            expression: tokens.join('+'),
            tokens: rawTokens
        }
    }

    /*  */

    function transformNode (el, options) {
        var warn = options.warn || baseWarn;
        var staticClass = getAndRemoveAttr(el, 'class');
        if (staticClass) {
            var res = parseText(staticClass, options.delimiters);
            if (res) {
                warn(
                    "class=\"" + staticClass + "\": " +
                    'Interpolation inside attributes has been removed. ' +
                    'Use v-bind or the colon shorthand instead. For example, ' +
                    'instead of <div class="{{ val }}">, use <div :class="val">.',
                    el.rawAttrsMap['class']
                );
            }
        }
        if (staticClass) {
            el.staticClass = JSON.stringify(staticClass);
        }
        var classBinding = getBindingAttr(el, 'class', false /* getStatic */);
        if (classBinding) {
            el.classBinding = classBinding;
        }
    }

    function genData (el) {
        var data = '';
        if (el.staticClass) {
            data += "staticClass:" + (el.staticClass) + ",";
        }
        if (el.classBinding) {
            data += "class:" + (el.classBinding) + ",";
        }
        return data
    }

    var klass$1 = {
        staticKeys: ['staticClass'],
        transformNode: transformNode,
        genData: genData
    };

    /*  */

    function transformNode$1 (el, options) {
        var warn = options.warn || baseWarn;
        var staticStyle = getAndRemoveAttr(el, 'style');
        if (staticStyle) {
            /* istanbul ignore if */
            {
                var res = parseText(staticStyle, options.delimiters);
                if (res) {
                    warn(
                        "style=\"" + staticStyle + "\": " +
                        'Interpolation inside attributes has been removed. ' +
                        'Use v-bind or the colon shorthand instead. For example, ' +
                        'instead of <div style="{{ val }}">, use <div :style="val">.',
                        el.rawAttrsMap['style']
                    );
                }
            }
            el.staticStyle = JSON.stringify(parseStyleText(staticStyle));
        }

        var styleBinding = getBindingAttr(el, 'style', false /* getStatic */);
        if (styleBinding) {
            el.styleBinding = styleBinding;
        }
    }

    function genData$1 (el) {
        var data = '';
        if (el.staticStyle) {
            data += "staticStyle:" + (el.staticStyle) + ",";
        }
        if (el.styleBinding) {
            data += "style:(" + (el.styleBinding) + "),";
        }
        return data
    }

    var style$1 = {
        staticKeys: ['staticStyle'],
        transformNode: transformNode$1,
        genData: genData$1
    };

    /*  */

    var decoder;

    var he = {
        decode: function decode (html) {
            decoder = decoder || document.createElement('div');
            decoder.innerHTML = html;
            return decoder.textContent
        }
    };

    /*  */

    var isUnaryTag = makeMap(
        'area,base,br,col,embed,frame,hr,img,input,isindex,keygen,' +
        'link,meta,param,source,track,wbr'
    );

    // Elements that you can, intentionally, leave open
    // (and which close themselves)
    var canBeLeftOpenTag = makeMap(
        'colgroup,dd,dt,li,options,p,td,tfoot,th,thead,tr,source'
    );

    // HTML5 tags https://html.spec.whatwg.org/multipage/indices.html#elements-3
    // Phrasing Content https://html.spec.whatwg.org/multipage/dom.html#phrasing-content
    var isNonPhrasingTag = makeMap(
        'address,article,aside,base,blockquote,body,caption,col,colgroup,dd,' +
        'details,dialog,div,dl,dt,fieldset,figcaption,figure,footer,form,' +
        'h1,h2,h3,h4,h5,h6,head,header,hgroup,hr,html,legend,li,menuitem,meta,' +
        'optgroup,option,param,rp,rt,source,style,summary,tbody,td,tfoot,th,thead,' +
        'title,tr,track'
    );

    /**
     * Not type-checking this file because it's mostly vendor code.
     */

    // Regular Expressions for parsing tags and attributes
    var attribute = /^\s*([^\s"'<>\/=]+)(?:\s*(=)\s*(?:"([^"]*)"+|'([^']*)'+|([^\s"'=<>`]+)))?/;
    var dynamicArgAttribute = /^\s*((?:v-[\w-]+:|@|:|#)\[[^=]+\][^\s"'<>\/=]*)(?:\s*(=)\s*(?:"([^"]*)"+|'([^']*)'+|([^\s"'=<>`]+)))?/;
    var ncname = "[a-zA-Z_][\\-\\.0-9_a-zA-Z" + (unicodeRegExp.source) + "]*";
    var qnameCapture = "((?:" + ncname + "\\:)?" + ncname + ")";
    var startTagOpen = new RegExp(("^<" + qnameCapture));
    var startTagClose = /^\s*(\/?)>/;
    var endTag = new RegExp(("^<\\/" + qnameCapture + "[^>]*>"));
    var doctype = /^<!DOCTYPE [^>]+>/i;
    // #7298: escape - to avoid being pased as HTML comment when inlined in page
    var comment = /^<!\--/;
    var conditionalComment = /^<!\[/;

    // Special Elements (can contain anything)
    var isPlainTextElement = makeMap('script,style,textarea', true);
    var reCache = {};

    var decodingMap = {
        '&lt;': '<',
        '&gt;': '>',
        '&quot;': '"',
        '&amp;': '&',
        '&#10;': '\n',
        '&#9;': '\t',
        '&#39;': "'"
    };
    var encodedAttr = /&(?:lt|gt|quot|amp|#39);/g;
    var encodedAttrWithNewLines = /&(?:lt|gt|quot|amp|#39|#10|#9);/g;

    // #5992
    var isIgnoreNewlineTag = makeMap('pre,textarea', true);
    var shouldIgnoreFirstNewline = function (tag, html) { return tag && isIgnoreNewlineTag(tag) && html[0] === '\n'; };

    function decodeAttr (value, shouldDecodeNewlines) {
        var re = shouldDecodeNewlines ? encodedAttrWithNewLines : encodedAttr;
        return value.replace(re, function (match) { return decodingMap[match]; })
    }

    function parseHTML (html, options) {
        var stack = [];
        var expectHTML = options.expectHTML;
        var isUnaryTag$$1 = options.isUnaryTag || no;
        var canBeLeftOpenTag$$1 = options.canBeLeftOpenTag || no;
        var index = 0;
        var last, lastTag;
        while (html) {
            last = html;
            // Make sure we're not in a plaintext content element like script/style
            if (!lastTag || !isPlainTextElement(lastTag)) {
                var textEnd = html.indexOf('<');
                if (textEnd === 0) {
                    // Comment:
                    if (comment.test(html)) {
                        var commentEnd = html.indexOf('-->');

                        if (commentEnd >= 0) {
                            if (options.shouldKeepComment) {
                                options.comment(html.substring(4, commentEnd), index, index + commentEnd + 3);
                            }
                            advance(commentEnd + 3);
                            continue
                        }
                    }

                    // http://en.wikipedia.org/wiki/Conditional_comment#Downlevel-revealed_conditional_comment
                    if (conditionalComment.test(html)) {
                        var conditionalEnd = html.indexOf(']>');

                        if (conditionalEnd >= 0) {
                            advance(conditionalEnd + 2);
                            continue
                        }
                    }

                    // Doctype:
                    var doctypeMatch = html.match(doctype);
                    if (doctypeMatch) {
                        advance(doctypeMatch[0].length);
                        continue
                    }

                    // End tag:
                    var endTagMatch = html.match(endTag);
                    if (endTagMatch) {
                        var curIndex = index;
                        advance(endTagMatch[0].length);
                        parseEndTag(endTagMatch[1], curIndex, index);
                        continue
                    }

                    // Start tag:
                    var startTagMatch = parseStartTag();
                    if (startTagMatch) {
                        handleStartTag(startTagMatch);
                        if (shouldIgnoreFirstNewline(startTagMatch.tagName, html)) {
                            advance(1);
                        }
                        continue
                    }
                }

                var text = (void 0), rest = (void 0), next = (void 0);
                if (textEnd >= 0) {
                    rest = html.slice(textEnd);
                    while (
                    !endTag.test(rest) &&
                    !startTagOpen.test(rest) &&
                    !comment.test(rest) &&
                    !conditionalComment.test(rest)
                        ) {
                        // < in plain text, be forgiving and treat it as text
                        next = rest.indexOf('<', 1);
                        if (next < 0) { break }
                        textEnd += next;
                        rest = html.slice(textEnd);
                    }
                    text = html.substring(0, textEnd);
                }

                if (textEnd < 0) {
                    text = html;
                }

                if (text) {
                    advance(text.length);
                }

                if (options.chars && text) {
                    options.chars(text, index - text.length, index);
                }
            } else {
                var endTagLength = 0;
                var stackedTag = lastTag.toLowerCase();
                var reStackedTag = reCache[stackedTag] || (reCache[stackedTag] = new RegExp('([\\s\\S]*?)(</' + stackedTag + '[^>]*>)', 'i'));
                var rest$1 = html.replace(reStackedTag, function (all, text, endTag) {
                    endTagLength = endTag.length;
                    if (!isPlainTextElement(stackedTag) && stackedTag !== 'noscript') {
                        text = text
                            .replace(/<!\--([\s\S]*?)-->/g, '$1') // #7298
                            .replace(/<!\[CDATA\[([\s\S]*?)]]>/g, '$1');
                    }
                    if (shouldIgnoreFirstNewline(stackedTag, text)) {
                        text = text.slice(1);
                    }
                    if (options.chars) {
                        options.chars(text);
                    }
                    return ''
                });
                index += html.length - rest$1.length;
                html = rest$1;
                parseEndTag(stackedTag, index - endTagLength, index);
            }

            if (html === last) {
                options.chars && options.chars(html);
                if (!stack.length && options.warn) {
                    options.warn(("Mal-formatted tag at end of template: \"" + html + "\""), { start: index + html.length });
                }
                break
            }
        }

        // Clean up any remaining tags
        parseEndTag();

        function advance (n) {
            index += n;
            html = html.substring(n);
        }

        function parseStartTag () {
            var start = html.match(startTagOpen);
            if (start) {
                var match = {
                    tagName: start[1],
                    attrs: [],
                    start: index
                };
                advance(start[0].length);
                var end, attr;
                while (!(end = html.match(startTagClose)) && (attr = html.match(dynamicArgAttribute) || html.match(attribute))) {
                    attr.start = index;
                    advance(attr[0].length);
                    attr.end = index;
                    match.attrs.push(attr);
                }
                if (end) {
                    match.unarySlash = end[1];
                    advance(end[0].length);
                    match.end = index;
                    return match
                }
            }
        }

        function handleStartTag (match) {
            var tagName = match.tagName;
            var unarySlash = match.unarySlash;

            if (expectHTML) {
                if (lastTag === 'p' && isNonPhrasingTag(tagName)) {
                    parseEndTag(lastTag);
                }
                if (canBeLeftOpenTag$$1(tagName) && lastTag === tagName) {
                    parseEndTag(tagName);
                }
            }

            var unary = isUnaryTag$$1(tagName) || !!unarySlash;

            var l = match.attrs.length;
            var attrs = new Array(l);
            for (var i = 0; i < l; i++) {
                var args = match.attrs[i];
                var value = args[3] || args[4] || args[5] || '';
                var shouldDecodeNewlines = tagName === 'a' && args[1] === 'href'
                    ? options.shouldDecodeNewlinesForHref
                    : options.shouldDecodeNewlines;
                attrs[i] = {
                    name: args[1],
                    value: decodeAttr(value, shouldDecodeNewlines)
                };
                if (options.outputSourceRange) {
                    attrs[i].start = args.start + args[0].match(/^\s*/).length;
                    attrs[i].end = args.end;
                }
            }

            if (!unary) {
                stack.push({ tag: tagName, lowerCasedTag: tagName.toLowerCase(), attrs: attrs, start: match.start, end: match.end });
                lastTag = tagName;
            }

            if (options.start) {
                options.start(tagName, attrs, unary, match.start, match.end);
            }
        }

        function parseEndTag (tagName, start, end) {
            var pos, lowerCasedTagName;
            if (start == null) { start = index; }
            if (end == null) { end = index; }

            // Find the closest opened tag of the same type
            if (tagName) {
                lowerCasedTagName = tagName.toLowerCase();
                for (pos = stack.length - 1; pos >= 0; pos--) {
                    if (stack[pos].lowerCasedTag === lowerCasedTagName) {
                        break
                    }
                }
            } else {
                // If no tag name is provided, clean shop
                pos = 0;
            }

            if (pos >= 0) {
                // Close all the open elements, up the stack
                for (var i = stack.length - 1; i >= pos; i--) {
                    if (i > pos || !tagName &&
                        options.warn
                    ) {
                        options.warn(
                            ("tag <" + (stack[i].tag) + "> has no matching end tag."),
                            { start: stack[i].start, end: stack[i].end }
                        );
                    }
                    if (options.end) {
                        options.end(stack[i].tag, start, end);
                    }
                }

                // Remove the open elements from the stack
                stack.length = pos;
                lastTag = pos && stack[pos - 1].tag;
            } else if (lowerCasedTagName === 'br') {
                if (options.start) {
                    options.start(tagName, [], true, start, end);
                }
            } else if (lowerCasedTagName === 'p') {
                if (options.start) {
                    options.start(tagName, [], false, start, end);
                }
                if (options.end) {
                    options.end(tagName, start, end);
                }
            }
        }
    }

    /*  */

    var onRE = /^@|^v-on:/;
    var dirRE = /^v-|^@|^:/;
    var forAliasRE = /([\s\S]*?)\s+(?:in|of)\s+([\s\S]*)/;
    var forIteratorRE = /,([^,\}\]]*)(?:,([^,\}\]]*))?$/;
    var stripParensRE = /^\(|\)$/g;
    var dynamicArgRE = /^\[.*\]$/;

    var argRE = /:(.*)$/;
    var bindRE = /^:|^\.|^v-bind:/;
    var modifierRE = /\.[^.\]]+(?=[^\]]*$)/g;

    var slotRE = /^v-slot(:|$)|^#/;

    var lineBreakRE = /[\r\n]/;
    var whitespaceRE$1 = /\s+/g;

    var invalidAttributeRE = /[\s"'<>\/=]/;

    var decodeHTMLCached = cached(he.decode);

    var emptySlotScopeToken = "_empty_";

    // configurable state
    var warn$2;
    var delimiters;
    var transforms;
    var preTransforms;
    var postTransforms;
    var platformIsPreTag;
    var platformMustUseProp;
    var platformGetTagNamespace;
    var maybeComponent;

    function createASTElement (
        tag,
        attrs,
        parent
    ) {
        return {
            type: 1,
            tag: tag,
            attrsList: attrs,
            attrsMap: makeAttrsMap(attrs),
            rawAttrsMap: {},
            parent: parent,
            children: []
        }
    }

    /**
     * Convert HTML string to AST.
     */
    function parse (
        template,
        options
    ) {
        warn$2 = options.warn || baseWarn;

        platformIsPreTag = options.isPreTag || no;
        platformMustUseProp = options.mustUseProp || no;
        platformGetTagNamespace = options.getTagNamespace || no;
        var isReservedTag = options.isReservedTag || no;
        maybeComponent = function (el) { return !!el.component || !isReservedTag(el.tag); };

        transforms = pluckModuleFunction(options.modules, 'transformNode');
        preTransforms = pluckModuleFunction(options.modules, 'preTransformNode');
        postTransforms = pluckModuleFunction(options.modules, 'postTransformNode');

        delimiters = options.delimiters;

        var stack = [];
        var preserveWhitespace = options.preserveWhitespace !== false;
        var whitespaceOption = options.whitespace;
        var root;
        var currentParent;
        var inVPre = false;
        var inPre = false;
        var warned = false;

        function warnOnce (msg, range) {
            if (!warned) {
                warned = true;
                warn$2(msg, range);
            }
        }

        function closeElement (element) {
            trimEndingWhitespace(element);
            if (!inVPre && !element.processed) {
                element = processElement(element, options);
            }
            // tree management
            if (!stack.length && element !== root) {
                // allow root elements with v-if, v-else-if and v-else
                if (root.if && (element.elseif || element.else)) {
                    {
                        checkRootConstraints(element);
                    }
                    addIfCondition(root, {
                        exp: element.elseif,
                        block: element
                    });
                } else {
                    warnOnce(
                        "Component template should contain exactly one root element. " +
                        "If you are using v-if on multiple elements, " +
                        "use v-else-if to chain them instead.",
                        { start: element.start }
                    );
                }
            }
            if (currentParent && !element.forbidden) {
                if (element.elseif || element.else) {
                    processIfConditions(element, currentParent);
                } else {
                    if (element.slotScope) {
                        // scoped slot
                        // keep it in the children list so that v-else(-if) conditions can
                        // find it as the prev node.
                        var name = element.slotTarget || '"default"'
                            ;(currentParent.scopedSlots || (currentParent.scopedSlots = {}))[name] = element;
                    }
                    currentParent.children.push(element);
                    element.parent = currentParent;
                }
            }

            // final children cleanup
            // filter out scoped slots
            element.children = element.children.filter(function (c) { return !(c).slotScope; });
            // remove trailing whitespace node again
            trimEndingWhitespace(element);

            // check pre state
            if (element.pre) {
                inVPre = false;
            }
            if (platformIsPreTag(element.tag)) {
                inPre = false;
            }
            // apply post-transforms
            for (var i = 0; i < postTransforms.length; i++) {
                postTransforms[i](element, options);
            }
        }

        function trimEndingWhitespace (el) {
            // remove trailing whitespace node
            if (!inPre) {
                var lastNode;
                while (
                (lastNode = el.children[el.children.length - 1]) &&
                lastNode.type === 3 &&
                lastNode.text === ' '
                    ) {
                    el.children.pop();
                }
            }
        }

        function checkRootConstraints (el) {
            if (el.tag === 'slot' || el.tag === 'template') {
                warnOnce(
                    "Cannot use <" + (el.tag) + "> as component root element because it may " +
                    'contain multiple nodes.',
                    { start: el.start }
                );
            }
            if (el.attrsMap.hasOwnProperty('v-for')) {
                warnOnce(
                    'Cannot use v-for on stateful component root element because ' +
                    'it renders multiple elements.',
                    el.rawAttrsMap['v-for']
                );
            }
        }

        parseHTML(template, {
            warn: warn$2,
            expectHTML: options.expectHTML,
            isUnaryTag: options.isUnaryTag,
            canBeLeftOpenTag: options.canBeLeftOpenTag,
            shouldDecodeNewlines: options.shouldDecodeNewlines,
            shouldDecodeNewlinesForHref: options.shouldDecodeNewlinesForHref,
            shouldKeepComment: options.comments,
            outputSourceRange: options.outputSourceRange,
            start: function start (tag, attrs, unary, start$1, end) {
                // check namespace.
                // inherit parent ns if there is one
                var ns = (currentParent && currentParent.ns) || platformGetTagNamespace(tag);

                // handle IE svg bug
                /* istanbul ignore if */
                if (isIE && ns === 'svg') {
                    attrs = guardIESVGBug(attrs);
                }

                var element = createASTElement(tag, attrs, currentParent);
                if (ns) {
                    element.ns = ns;
                }

                {
                    if (options.outputSourceRange) {
                        element.start = start$1;
                        element.end = end;
                        element.rawAttrsMap = element.attrsList.reduce(function (cumulated, attr) {
                            cumulated[attr.name] = attr;
                            return cumulated
                        }, {});
                    }
                    attrs.forEach(function (attr) {
                        if (invalidAttributeRE.test(attr.name)) {
                            warn$2(
                                "Invalid dynamic argument expression: attribute names cannot contain " +
                                "spaces, quotes, <, >, / or =.",
                                {
                                    start: attr.start + attr.name.indexOf("["),
                                    end: attr.start + attr.name.length
                                }
                            );
                        }
                    });
                }

                if (isForbiddenTag(element) && !isServerRendering()) {
                    element.forbidden = true;
                    warn$2(
                        'Templates should only be responsible for mapping the state to the ' +
                        'UI. Avoid placing tags with side-effects in your templates, such as ' +
                        "<" + tag + ">" + ', as they will not be parsed.',
                        { start: element.start }
                    );
                }

                // apply pre-transforms
                for (var i = 0; i < preTransforms.length; i++) {
                    element = preTransforms[i](element, options) || element;
                }

                if (!inVPre) {
                    processPre(element);
                    if (element.pre) {
                        inVPre = true;
                    }
                }
                if (platformIsPreTag(element.tag)) {
                    inPre = true;
                }
                if (inVPre) {
                    processRawAttrs(element);
                } else if (!element.processed) {
                    // structural directives
                    processFor(element);
                    processIf(element);
                    processOnce(element);
                }

                if (!root) {
                    root = element;
                    {
                        checkRootConstraints(root);
                    }
                }

                if (!unary) {
                    currentParent = element;
                    stack.push(element);
                } else {
                    closeElement(element);
                }
            },

            end: function end (tag, start, end$1) {
                var element = stack[stack.length - 1];
                // pop stack
                stack.length -= 1;
                currentParent = stack[stack.length - 1];
                if (options.outputSourceRange) {
                    element.end = end$1;
                }
                closeElement(element);
            },

            chars: function chars (text, start, end) {
                if (!currentParent) {
                    {
                        if (text === template) {
                            warnOnce(
                                'Component template requires a root element, rather than just text.',
                                { start: start }
                            );
                        } else if ((text = text.trim())) {
                            warnOnce(
                                ("text \"" + text + "\" outside root element will be ignored."),
                                { start: start }
                            );
                        }
                    }
                    return
                }
                // IE textarea placeholder bug
                /* istanbul ignore if */
                if (isIE &&
                    currentParent.tag === 'textarea' &&
                    currentParent.attrsMap.placeholder === text
                ) {
                    return
                }
                var children = currentParent.children;
                if (inPre || text.trim()) {
                    text = isTextTag(currentParent) ? text : decodeHTMLCached(text);
                } else if (!children.length) {
                    // remove the whitespace-only node right after an opening tag
                    text = '';
                } else if (whitespaceOption) {
                    if (whitespaceOption === 'condense') {
                        // in condense mode, remove the whitespace node if it contains
                        // line break, otherwise condense to a single space
                        text = lineBreakRE.test(text) ? '' : ' ';
                    } else {
                        text = ' ';
                    }
                } else {
                    text = preserveWhitespace ? ' ' : '';
                }
                if (text) {
                    if (!inPre && whitespaceOption === 'condense') {
                        // condense consecutive whitespaces into single space
                        text = text.replace(whitespaceRE$1, ' ');
                    }
                    var res;
                    var child;
                    if (!inVPre && text !== ' ' && (res = parseText(text, delimiters))) {
                        child = {
                            type: 2,
                            expression: res.expression,
                            tokens: res.tokens,
                            text: text
                        };
                    } else if (text !== ' ' || !children.length || children[children.length - 1].text !== ' ') {
                        child = {
                            type: 3,
                            text: text
                        };
                    }
                    if (child) {
                        if (options.outputSourceRange) {
                            child.start = start;
                            child.end = end;
                        }
                        children.push(child);
                    }
                }
            },
            comment: function comment (text, start, end) {
                // adding anyting as a sibling to the root node is forbidden
                // comments should still be allowed, but ignored
                if (currentParent) {
                    var child = {
                        type: 3,
                        text: text,
                        isComment: true
                    };
                    if (options.outputSourceRange) {
                        child.start = start;
                        child.end = end;
                    }
                    currentParent.children.push(child);
                }
            }
        });
        return root
    }

    function processPre (el) {
        if (getAndRemoveAttr(el, 'v-pre') != null) {
            el.pre = true;
        }
    }

    function processRawAttrs (el) {
        var list = el.attrsList;
        var len = list.length;
        if (len) {
            var attrs = el.attrs = new Array(len);
            for (var i = 0; i < len; i++) {
                attrs[i] = {
                    name: list[i].name,
                    value: JSON.stringify(list[i].value)
                };
                if (list[i].start != null) {
                    attrs[i].start = list[i].start;
                    attrs[i].end = list[i].end;
                }
            }
        } else if (!el.pre) {
            // non root node in pre blocks with no attributes
            el.plain = true;
        }
    }

    function processElement (
        element,
        options
    ) {
        processKey(element);

        // determine whether this is a plain element after
        // removing structural attributes
        element.plain = (
            !element.key &&
            !element.scopedSlots &&
            !element.attrsList.length
        );

        processRef(element);
        processSlotContent(element);
        processSlotOutlet(element);
        processComponent(element);
        for (var i = 0; i < transforms.length; i++) {
            element = transforms[i](element, options) || element;
        }
        processAttrs(element);
        return element
    }

    function processKey (el) {
        var exp = getBindingAttr(el, 'key');
        if (exp) {
            {
                if (el.tag === 'template') {
                    warn$2(
                        "<template> cannot be keyed. Place the key on real elements instead.",
                        getRawBindingAttr(el, 'key')
                    );
                }
                if (el.for) {
                    var iterator = el.iterator2 || el.iterator1;
                    var parent = el.parent;
                    if (iterator && iterator === exp && parent && parent.tag === 'transition-group') {
                        warn$2(
                            "Do not use v-for index as key on <transition-group> children, " +
                            "this is the same as not using keys.",
                            getRawBindingAttr(el, 'key'),
                            true /* tip */
                        );
                    }
                }
            }
            el.key = exp;
        }
    }

    function processRef (el) {
        var ref = getBindingAttr(el, 'ref');
        if (ref) {
            el.ref = ref;
            el.refInFor = checkInFor(el);
        }
    }

    function processFor (el) {
        var exp;
        if ((exp = getAndRemoveAttr(el, 'v-for'))) {
            var res = parseFor(exp);
            if (res) {
                extend(el, res);
            } else {
                warn$2(
                    ("Invalid v-for expression: " + exp),
                    el.rawAttrsMap['v-for']
                );
            }
        }
    }



    function parseFor (exp) {
        var inMatch = exp.match(forAliasRE);
        if (!inMatch) { return }
        var res = {};
        res.for = inMatch[2].trim();
        var alias = inMatch[1].trim().replace(stripParensRE, '');
        var iteratorMatch = alias.match(forIteratorRE);
        if (iteratorMatch) {
            res.alias = alias.replace(forIteratorRE, '').trim();
            res.iterator1 = iteratorMatch[1].trim();
            if (iteratorMatch[2]) {
                res.iterator2 = iteratorMatch[2].trim();
            }
        } else {
            res.alias = alias;
        }
        return res
    }

    function processIf (el) {
        var exp = getAndRemoveAttr(el, 'v-if');
        if (exp) {
            el.if = exp;
            addIfCondition(el, {
                exp: exp,
                block: el
            });
        } else {
            if (getAndRemoveAttr(el, 'v-else') != null) {
                el.else = true;
            }
            var elseif = getAndRemoveAttr(el, 'v-else-if');
            if (elseif) {
                el.elseif = elseif;
            }
        }
    }

    function processIfConditions (el, parent) {
        var prev = findPrevElement(parent.children);
        if (prev && prev.if) {
            addIfCondition(prev, {
                exp: el.elseif,
                block: el
            });
        } else {
            warn$2(
                "v-" + (el.elseif ? ('else-if="' + el.elseif + '"') : 'else') + " " +
                "used on element <" + (el.tag) + "> without corresponding v-if.",
                el.rawAttrsMap[el.elseif ? 'v-else-if' : 'v-else']
            );
        }
    }

    function findPrevElement (children) {
        var i = children.length;
        while (i--) {
            if (children[i].type === 1) {
                return children[i]
            } else {
                if (children[i].text !== ' ') {
                    warn$2(
                        "text \"" + (children[i].text.trim()) + "\" between v-if and v-else(-if) " +
                        "will be ignored.",
                        children[i]
                    );
                }
                children.pop();
            }
        }
    }

    function addIfCondition (el, condition) {
        if (!el.ifConditions) {
            el.ifConditions = [];
        }
        el.ifConditions.push(condition);
    }

    function processOnce (el) {
        var once$$1 = getAndRemoveAttr(el, 'v-once');
        if (once$$1 != null) {
            el.once = true;
        }
    }

    // handle content being passed to a component as slot,
    // e.g. <template slot="xxx">, <div slot-scope="xxx">
    function processSlotContent (el) {
        var slotScope;
        if (el.tag === 'template') {
            slotScope = getAndRemoveAttr(el, 'scope');
            /* istanbul ignore if */
            if (slotScope) {
                warn$2(
                    "the \"scope\" attribute for scoped slots have been deprecated and " +
                    "replaced by \"slot-scope\" since 2.5. The new \"slot-scope\" attribute " +
                    "can also be used on plain elements in addition to <template> to " +
                    "denote scoped slots.",
                    el.rawAttrsMap['scope'],
                    true
                );
            }
            el.slotScope = slotScope || getAndRemoveAttr(el, 'slot-scope');
        } else if ((slotScope = getAndRemoveAttr(el, 'slot-scope'))) {
            /* istanbul ignore if */
            if (el.attrsMap['v-for']) {
                warn$2(
                    "Ambiguous combined usage of slot-scope and v-for on <" + (el.tag) + "> " +
                    "(v-for takes higher priority). Use a wrapper <template> for the " +
                    "scoped slot to make it clearer.",
                    el.rawAttrsMap['slot-scope'],
                    true
                );
            }
            el.slotScope = slotScope;
        }

        // slot="xxx"
        var slotTarget = getBindingAttr(el, 'slot');
        if (slotTarget) {
            el.slotTarget = slotTarget === '""' ? '"default"' : slotTarget;
            el.slotTargetDynamic = !!(el.attrsMap[':slot'] || el.attrsMap['v-bind:slot']);
            // preserve slot as an attribute for native shadow DOM compat
            // only for non-scoped slots.
            if (el.tag !== 'template' && !el.slotScope) {
                addAttr(el, 'slot', slotTarget, getRawBindingAttr(el, 'slot'));
            }
        }

        // 2.6 v-slot syntax
        {
            if (el.tag === 'template') {
                // v-slot on <template>
                var slotBinding = getAndRemoveAttrByRegex(el, slotRE);
                if (slotBinding) {
                    {
                        if (el.slotTarget || el.slotScope) {
                            warn$2(
                                "Unexpected mixed usage of different slot syntaxes.",
                                el
                            );
                        }
                        if (el.parent && !maybeComponent(el.parent)) {
                            warn$2(
                                "<template v-slot> can only appear at the root level inside " +
                                "the receiving the component",
                                el
                            );
                        }
                    }
                    var ref = getSlotName(slotBinding);
                    var name = ref.name;
                    var dynamic = ref.dynamic;
                    el.slotTarget = name;
                    el.slotTargetDynamic = dynamic;
                    el.slotScope = slotBinding.value || emptySlotScopeToken; // force it into a scoped slot for perf
                }
            } else {
                // v-slot on component, denotes default slot
                var slotBinding$1 = getAndRemoveAttrByRegex(el, slotRE);
                if (slotBinding$1) {
                    {
                        if (!maybeComponent(el)) {
                            warn$2(
                                "v-slot can only be used on components or <template>.",
                                slotBinding$1
                            );
                        }
                        if (el.slotScope || el.slotTarget) {
                            warn$2(
                                "Unexpected mixed usage of different slot syntaxes.",
                                el
                            );
                        }
                        if (el.scopedSlots) {
                            warn$2(
                                "To avoid scope ambiguity, the default slot should also use " +
                                "<template> syntax when there are other named slots.",
                                slotBinding$1
                            );
                        }
                    }
                    // add the component's children to its default slot
                    var slots = el.scopedSlots || (el.scopedSlots = {});
                    var ref$1 = getSlotName(slotBinding$1);
                    var name$1 = ref$1.name;
                    var dynamic$1 = ref$1.dynamic;
                    var slotContainer = slots[name$1] = createASTElement('template', [], el);
                    slotContainer.slotTarget = name$1;
                    slotContainer.slotTargetDynamic = dynamic$1;
                    slotContainer.children = el.children.filter(function (c) {
                        if (!c.slotScope) {
                            c.parent = slotContainer;
                            return true
                        }
                    });
                    slotContainer.slotScope = slotBinding$1.value || emptySlotScopeToken;
                    // remove children as they are returned from scopedSlots now
                    el.children = [];
                    // mark el non-plain so data gets generated
                    el.plain = false;
                }
            }
        }
    }

    function getSlotName (binding) {
        var name = binding.name.replace(slotRE, '');
        if (!name) {
            if (binding.name[0] !== '#') {
                name = 'default';
            } else {
                warn$2(
                    "v-slot shorthand syntax requires a slot name.",
                    binding
                );
            }
        }
        return dynamicArgRE.test(name)
            // dynamic [name]
            ? { name: name.slice(1, -1), dynamic: true }
            // static name
            : { name: ("\"" + name + "\""), dynamic: false }
    }

    // handle <slot/> outlets
    function processSlotOutlet (el) {
        if (el.tag === 'slot') {
            el.slotName = getBindingAttr(el, 'name');
            if (el.key) {
                warn$2(
                    "`key` does not work on <slot> because slots are abstract outlets " +
                    "and can possibly expand into multiple elements. " +
                    "Use the key on a wrapping element instead.",
                    getRawBindingAttr(el, 'key')
                );
            }
        }
    }

    function processComponent (el) {
        var binding;
        if ((binding = getBindingAttr(el, 'is'))) {
            el.component = binding;
        }
        if (getAndRemoveAttr(el, 'inline-template') != null) {
            el.inlineTemplate = true;
        }
    }

    function processAttrs (el) {
        var list = el.attrsList;
        var i, l, name, rawName, value, modifiers, syncGen, isDynamic;
        for (i = 0, l = list.length; i < l; i++) {
            name = rawName = list[i].name;
            value = list[i].value;
            if (dirRE.test(name)) {
                // mark element as dynamic
                el.hasBindings = true;
                // modifiers
                modifiers = parseModifiers(name.replace(dirRE, ''));
                // support .foo shorthand syntax for the .prop modifier
                if (modifiers) {
                    name = name.replace(modifierRE, '');
                }
                if (bindRE.test(name)) { // v-bind
                    name = name.replace(bindRE, '');
                    value = parseFilters(value);
                    isDynamic = dynamicArgRE.test(name);
                    if (isDynamic) {
                        name = name.slice(1, -1);
                    }
                    if (
                        value.trim().length === 0
                    ) {
                        warn$2(
                            ("The value for a v-bind expression cannot be empty. Found in \"v-bind:" + name + "\"")
                        );
                    }
                    if (modifiers) {
                        if (modifiers.prop && !isDynamic) {
                            name = camelize(name);
                            if (name === 'innerHtml') { name = 'innerHTML'; }
                        }
                        if (modifiers.camel && !isDynamic) {
                            name = camelize(name);
                        }
                        if (modifiers.sync) {
                            syncGen = genAssignmentCode(value, "$event");
                            if (!isDynamic) {
                                addHandler(
                                    el,
                                    ("update:" + (camelize(name))),
                                    syncGen,
                                    null,
                                    false,
                                    warn$2,
                                    list[i]
                                );
                                if (hyphenate(name) !== camelize(name)) {
                                    addHandler(
                                        el,
                                        ("update:" + (hyphenate(name))),
                                        syncGen,
                                        null,
                                        false,
                                        warn$2,
                                        list[i]
                                    );
                                }
                            } else {
                                // handler w/ dynamic event name
                                addHandler(
                                    el,
                                    ("\"update:\"+(" + name + ")"),
                                    syncGen,
                                    null,
                                    false,
                                    warn$2,
                                    list[i],
                                    true // dynamic
                                );
                            }
                        }
                    }
                    if ((modifiers && modifiers.prop) || (
                            !el.component && platformMustUseProp(el.tag, el.attrsMap.type, name)
                        )) {
                        addProp(el, name, value, list[i], isDynamic);
                    } else {
                        addAttr(el, name, value, list[i], isDynamic);
                    }
                } else if (onRE.test(name)) { // v-on
                    name = name.replace(onRE, '');
                    isDynamic = dynamicArgRE.test(name);
                    if (isDynamic) {
                        name = name.slice(1, -1);
                    }
                    addHandler(el, name, value, modifiers, false, warn$2, list[i], isDynamic);
                } else { // normal directives
                    name = name.replace(dirRE, '');
                    // parse arg
                    var argMatch = name.match(argRE);
                    var arg = argMatch && argMatch[1];
                    isDynamic = false;
                    if (arg) {
                        name = name.slice(0, -(arg.length + 1));
                        if (dynamicArgRE.test(arg)) {
                            arg = arg.slice(1, -1);
                            isDynamic = true;
                        }
                    }
                    addDirective(el, name, rawName, value, arg, isDynamic, modifiers, list[i]);
                    if (name === 'model') {
                        checkForAliasModel(el, value);
                    }
                }
            } else {
                // literal attribute
                {
                    var res = parseText(value, delimiters);
                    if (res) {
                        warn$2(
                            name + "=\"" + value + "\": " +
                            'Interpolation inside attributes has been removed. ' +
                            'Use v-bind or the colon shorthand instead. For example, ' +
                            'instead of <div id="{{ val }}">, use <div :id="val">.',
                            list[i]
                        );
                    }
                }
                addAttr(el, name, JSON.stringify(value), list[i]);
                // #6887 firefox doesn't update muted state if set via attribute
                // even immediately after element creation
                if (!el.component &&
                    name === 'muted' &&
                    platformMustUseProp(el.tag, el.attrsMap.type, name)) {
                    addProp(el, name, 'true', list[i]);
                }
            }
        }
    }

    function checkInFor (el) {
        var parent = el;
        while (parent) {
            if (parent.for !== undefined) {
                return true
            }
            parent = parent.parent;
        }
        return false
    }

    function parseModifiers (name) {
        var match = name.match(modifierRE);
        if (match) {
            var ret = {};
            match.forEach(function (m) { ret[m.slice(1)] = true; });
            return ret
        }
    }

    function makeAttrsMap (attrs) {
        var map = {};
        for (var i = 0, l = attrs.length; i < l; i++) {
            if (
                map[attrs[i].name] && !isIE && !isEdge
            ) {
                warn$2('duplicate attribute: ' + attrs[i].name, attrs[i]);
            }
            map[attrs[i].name] = attrs[i].value;
        }
        return map
    }

    // for script (e.g. type="x/template") or style, do not decode content
    function isTextTag (el) {
        return el.tag === 'script' || el.tag === 'style'
    }

    function isForbiddenTag (el) {
        return (
            el.tag === 'style' ||
            (el.tag === 'script' && (
                !el.attrsMap.type ||
                el.attrsMap.type === 'text/javascript'
            ))
        )
    }

    var ieNSBug = /^xmlns:NS\d+/;
    var ieNSPrefix = /^NS\d+:/;

    /* istanbul ignore next */
    function guardIESVGBug (attrs) {
        var res = [];
        for (var i = 0; i < attrs.length; i++) {
            var attr = attrs[i];
            if (!ieNSBug.test(attr.name)) {
                attr.name = attr.name.replace(ieNSPrefix, '');
                res.push(attr);
            }
        }
        return res
    }

    function checkForAliasModel (el, value) {
        var _el = el;
        while (_el) {
            if (_el.for && _el.alias === value) {
                warn$2(
                    "<" + (el.tag) + " v-model=\"" + value + "\">: " +
                    "You are binding v-model directly to a v-for iteration alias. " +
                    "This will not be able to modify the v-for source array because " +
                    "writing to the alias is like modifying a function local variable. " +
                    "Consider using an array of objects and use v-model on an object property instead.",
                    el.rawAttrsMap['v-model']
                );
            }
            _el = _el.parent;
        }
    }

    /*  */

    function preTransformNode (el, options) {
        if (el.tag === 'input') {
            var map = el.attrsMap;
            if (!map['v-model']) {
                return
            }

            var typeBinding;
            if (map[':type'] || map['v-bind:type']) {
                typeBinding = getBindingAttr(el, 'type');
            }
            if (!map.type && !typeBinding && map['v-bind']) {
                typeBinding = "(" + (map['v-bind']) + ").type";
            }

            if (typeBinding) {
                var ifCondition = getAndRemoveAttr(el, 'v-if', true);
                var ifConditionExtra = ifCondition ? ("&&(" + ifCondition + ")") : "";
                var hasElse = getAndRemoveAttr(el, 'v-else', true) != null;
                var elseIfCondition = getAndRemoveAttr(el, 'v-else-if', true);
                // 1. checkbox
                var branch0 = cloneASTElement(el);
                // process for on the main node
                processFor(branch0);
                addRawAttr(branch0, 'type', 'checkbox');
                processElement(branch0, options);
                branch0.processed = true; // prevent it from double-processed
                branch0.if = "(" + typeBinding + ")==='checkbox'" + ifConditionExtra;
                addIfCondition(branch0, {
                    exp: branch0.if,
                    block: branch0
                });
                // 2. add radio else-if condition
                var branch1 = cloneASTElement(el);
                getAndRemoveAttr(branch1, 'v-for', true);
                addRawAttr(branch1, 'type', 'radio');
                processElement(branch1, options);
                addIfCondition(branch0, {
                    exp: "(" + typeBinding + ")==='radio'" + ifConditionExtra,
                    block: branch1
                });
                // 3. other
                var branch2 = cloneASTElement(el);
                getAndRemoveAttr(branch2, 'v-for', true);
                addRawAttr(branch2, ':type', typeBinding);
                processElement(branch2, options);
                addIfCondition(branch0, {
                    exp: ifCondition,
                    block: branch2
                });

                if (hasElse) {
                    branch0.else = true;
                } else if (elseIfCondition) {
                    branch0.elseif = elseIfCondition;
                }

                return branch0
            }
        }
    }

    function cloneASTElement (el) {
        return createASTElement(el.tag, el.attrsList.slice(), el.parent)
    }

    var model$1 = {
        preTransformNode: preTransformNode
    };

    var modules$1 = [
        klass$1,
        style$1,
        model$1
    ];

    /*  */

    function text (el, dir) {
        if (dir.value) {
            addProp(el, 'textContent', ("_s(" + (dir.value) + ")"), dir);
        }
    }

    /*  */

    function html (el, dir) {
        if (dir.value) {
            addProp(el, 'innerHTML', ("_s(" + (dir.value) + ")"), dir);
        }
    }

    var directives$1 = {
        model: model,
        text: text,
        html: html
    };

    /*  */

    var baseOptions = {
        expectHTML: true,
        modules: modules$1,
        directives: directives$1,
        isPreTag: isPreTag,
        isUnaryTag: isUnaryTag,
        mustUseProp: mustUseProp,
        canBeLeftOpenTag: canBeLeftOpenTag,
        isReservedTag: isReservedTag,
        getTagNamespace: getTagNamespace,
        staticKeys: genStaticKeys(modules$1)
    };

    /*  */

    var isStaticKey;
    var isPlatformReservedTag;

    var genStaticKeysCached = cached(genStaticKeys$1);

    /**
     * Goal of the optimizer: walk the generated template AST tree
     * and detect sub-trees that are purely static, i.e. parts of
     * the DOM that never needs to change.
     *
     * Once we detect these sub-trees, we can:
     *
     * 1. Hoist them into constants, so that we no longer need to
     *    create fresh nodes for them on each re-render;
     * 2. Completely skip them in the patching process.
     */
    function optimize (root, options) {
        if (!root) { return }
        isStaticKey = genStaticKeysCached(options.staticKeys || '');
        isPlatformReservedTag = options.isReservedTag || no;
        // first pass: mark all non-static nodes.
        markStatic$1(root);
        // second pass: mark static roots.
        markStaticRoots(root, false);
    }

    function genStaticKeys$1 (keys) {
        return makeMap(
            'type,tag,attrsList,attrsMap,plain,parent,children,attrs,start,end,rawAttrsMap' +
            (keys ? ',' + keys : '')
        )
    }

    function markStatic$1 (node) {
        node.static = isStatic(node);
        if (node.type === 1) {
            // do not make component slot content static. this avoids
            // 1. components not able to mutate slot nodes
            // 2. static slot content fails for hot-reloading
            if (
                !isPlatformReservedTag(node.tag) &&
                node.tag !== 'slot' &&
                node.attrsMap['inline-template'] == null
            ) {
                return
            }
            for (var i = 0, l = node.children.length; i < l; i++) {
                var child = node.children[i];
                markStatic$1(child);
                if (!child.static) {
                    node.static = false;
                }
            }
            if (node.ifConditions) {
                for (var i$1 = 1, l$1 = node.ifConditions.length; i$1 < l$1; i$1++) {
                    var block = node.ifConditions[i$1].block;
                    markStatic$1(block);
                    if (!block.static) {
                        node.static = false;
                    }
                }
            }
        }
    }

    function markStaticRoots (node, isInFor) {
        if (node.type === 1) {
            if (node.static || node.once) {
                node.staticInFor = isInFor;
            }
            // For a node to qualify as a static root, it should have children that
            // are not just static text. Otherwise the cost of hoisting out will
            // outweigh the benefits and it's better off to just always render it fresh.
            if (node.static && node.children.length && !(
                    node.children.length === 1 &&
                    node.children[0].type === 3
                )) {
                node.staticRoot = true;
                return
            } else {
                node.staticRoot = false;
            }
            if (node.children) {
                for (var i = 0, l = node.children.length; i < l; i++) {
                    markStaticRoots(node.children[i], isInFor || !!node.for);
                }
            }
            if (node.ifConditions) {
                for (var i$1 = 1, l$1 = node.ifConditions.length; i$1 < l$1; i$1++) {
                    markStaticRoots(node.ifConditions[i$1].block, isInFor);
                }
            }
        }
    }

    function isStatic (node) {
        if (node.type === 2) { // expression
            return false
        }
        if (node.type === 3) { // text
            return true
        }
        return !!(node.pre || (
            !node.hasBindings && // no dynamic bindings
            !node.if && !node.for && // not v-if or v-for or v-else
            !isBuiltInTag(node.tag) && // not a built-in
            isPlatformReservedTag(node.tag) && // not a component
            !isDirectChildOfTemplateFor(node) &&
            Object.keys(node).every(isStaticKey)
        ))
    }

    function isDirectChildOfTemplateFor (node) {
        while (node.parent) {
            node = node.parent;
            if (node.tag !== 'template') {
                return false
            }
            if (node.for) {
                return true
            }
        }
        return false
    }

    /*  */

    var fnExpRE = /^([\w$_]+|\([^)]*?\))\s*=>|^function\s*(?:[\w$]+)?\s*\(/;
    var fnInvokeRE = /\([^)]*?\);*$/;
    var simplePathRE = /^[A-Za-z_$][\w$]*(?:\.[A-Za-z_$][\w$]*|\['[^']*?']|\["[^"]*?"]|\[\d+]|\[[A-Za-z_$][\w$]*])*$/;

    // KeyboardEvent.keyCode aliases
    var keyCodes = {
        esc: 27,
        tab: 9,
        enter: 13,
        space: 32,
        up: 38,
        left: 37,
        right: 39,
        down: 40,
        'delete': [8, 46]
    };

    // KeyboardEvent.key aliases
    var keyNames = {
        // #7880: IE11 and Edge use `Esc` for Escape key name.
        esc: ['Esc', 'Escape'],
        tab: 'Tab',
        enter: 'Enter',
        // #9112: IE11 uses `Spacebar` for Space key name.
        space: [' ', 'Spacebar'],
        // #7806: IE11 uses key names without `Arrow` prefix for arrow keys.
        up: ['Up', 'ArrowUp'],
        left: ['Left', 'ArrowLeft'],
        right: ['Right', 'ArrowRight'],
        down: ['Down', 'ArrowDown'],
        // #9112: IE11 uses `Del` for Delete key name.
        'delete': ['Backspace', 'Delete', 'Del']
    };

    // #4868: modifiers that prevent the execution of the listener
    // need to explicitly return null so that we can determine whether to remove
    // the listener for .once
    var genGuard = function (condition) { return ("if(" + condition + ")return null;"); };

    var modifierCode = {
        stop: '$event.stopPropagation();',
        prevent: '$event.preventDefault();',
        self: genGuard("$event.target !== $event.currentTarget"),
        ctrl: genGuard("!$event.ctrlKey"),
        shift: genGuard("!$event.shiftKey"),
        alt: genGuard("!$event.altKey"),
        meta: genGuard("!$event.metaKey"),
        left: genGuard("'button' in $event && $event.button !== 0"),
        middle: genGuard("'button' in $event && $event.button !== 1"),
        right: genGuard("'button' in $event && $event.button !== 2")
    };

    function genHandlers (
        events,
        isNative
    ) {
        var prefix = isNative ? 'nativeOn:' : 'on:';
        var staticHandlers = "";
        var dynamicHandlers = "";
        for (var name in events) {
            var handlerCode = genHandler(events[name]);
            if (events[name] && events[name].dynamic) {
                dynamicHandlers += name + "," + handlerCode + ",";
            } else {
                staticHandlers += "\"" + name + "\":" + handlerCode + ",";
            }
        }
        staticHandlers = "{" + (staticHandlers.slice(0, -1)) + "}";
        if (dynamicHandlers) {
            return prefix + "_d(" + staticHandlers + ",[" + (dynamicHandlers.slice(0, -1)) + "])"
        } else {
            return prefix + staticHandlers
        }
    }

    function genHandler (handler) {
        if (!handler) {
            return 'function(){}'
        }

        if (Array.isArray(handler)) {
            return ("[" + (handler.map(function (handler) { return genHandler(handler); }).join(',')) + "]")
        }

        var isMethodPath = simplePathRE.test(handler.value);
        var isFunctionExpression = fnExpRE.test(handler.value);
        var isFunctionInvocation = simplePathRE.test(handler.value.replace(fnInvokeRE, ''));

        if (!handler.modifiers) {
            if (isMethodPath || isFunctionExpression) {
                return handler.value
            }
            return ("function($event){" + (isFunctionInvocation ? ("return " + (handler.value)) : handler.value) + "}") // inline statement
        } else {
            var code = '';
            var genModifierCode = '';
            var keys = [];
            for (var key in handler.modifiers) {
                if (modifierCode[key]) {
                    genModifierCode += modifierCode[key];
                    // left/right
                    if (keyCodes[key]) {
                        keys.push(key);
                    }
                } else if (key === 'exact') {
                    var modifiers = (handler.modifiers);
                    genModifierCode += genGuard(
                        ['ctrl', 'shift', 'alt', 'meta']
                            .filter(function (keyModifier) { return !modifiers[keyModifier]; })
                            .map(function (keyModifier) { return ("$event." + keyModifier + "Key"); })
                            .join('||')
                    );
                } else {
                    keys.push(key);
                }
            }
            if (keys.length) {
                code += genKeyFilter(keys);
            }
            // Make sure modifiers like prevent and stop get executed after key filtering
            if (genModifierCode) {
                code += genModifierCode;
            }
            var handlerCode = isMethodPath
                ? ("return " + (handler.value) + "($event)")
                : isFunctionExpression
                ? ("return (" + (handler.value) + ")($event)")
                : isFunctionInvocation
                ? ("return " + (handler.value))
                : handler.value;
            return ("function($event){" + code + handlerCode + "}")
        }
    }

    function genKeyFilter (keys) {
        return (
            // make sure the key filters only apply to KeyboardEvents
            // #9441: can't use 'keyCode' in $event because Chrome autofill fires fake
            // key events that do not have keyCode property...
            "if(!$event.type.indexOf('key')&&" +
            (keys.map(genFilterCode).join('&&')) + ")return null;"
        )
    }

    function genFilterCode (key) {
        var keyVal = parseInt(key, 10);
        if (keyVal) {
            return ("$event.keyCode!==" + keyVal)
        }
        var keyCode = keyCodes[key];
        var keyName = keyNames[key];
        return (
            "_k($event.keyCode," +
            (JSON.stringify(key)) + "," +
            (JSON.stringify(keyCode)) + "," +
            "$event.key," +
            "" + (JSON.stringify(keyName)) +
            ")"
        )
    }

    /*  */

    function on (el, dir) {
        if (dir.modifiers) {
            warn("v-on without argument does not support modifiers.");
        }
        el.wrapListeners = function (code) { return ("_g(" + code + "," + (dir.value) + ")"); };
    }

    /*  */

    function bind$1 (el, dir) {
        el.wrapData = function (code) {
            return ("_b(" + code + ",'" + (el.tag) + "'," + (dir.value) + "," + (dir.modifiers && dir.modifiers.prop ? 'true' : 'false') + (dir.modifiers && dir.modifiers.sync ? ',true' : '') + ")")
        };
    }

    /*  */

    var baseDirectives = {
        on: on,
        bind: bind$1,
        cloak: noop
    };

    /*  */





    var CodegenState = function CodegenState (options) {
        this.options = options;
        this.warn = options.warn || baseWarn;
        this.transforms = pluckModuleFunction(options.modules, 'transformCode');
        this.dataGenFns = pluckModuleFunction(options.modules, 'genData');
        this.directives = extend(extend({}, baseDirectives), options.directives);
        var isReservedTag = options.isReservedTag || no;
        this.maybeComponent = function (el) { return !!el.component || !isReservedTag(el.tag); };
        this.onceId = 0;
        this.staticRenderFns = [];
        this.pre = false;
    };



    function generate (
        ast,
        options
    ) {
        var state = new CodegenState(options);
        var code = ast ? genElement(ast, state) : '_c("div")';
        return {
            render: ("with(this){return " + code + "}"),
            staticRenderFns: state.staticRenderFns
        }
    }

    function genElement (el, state) {
        if (el.parent) {
            el.pre = el.pre || el.parent.pre;
        }

        if (el.staticRoot && !el.staticProcessed) {
            return genStatic(el, state)
        } else if (el.once && !el.onceProcessed) {
            return genOnce(el, state)
        } else if (el.for && !el.forProcessed) {
            return genFor(el, state)
        } else if (el.if && !el.ifProcessed) {
            return genIf(el, state)
        } else if (el.tag === 'template' && !el.slotTarget && !state.pre) {
            return genChildren(el, state) || 'void 0'
        } else if (el.tag === 'slot') {
            return genSlot(el, state)
        } else {
            // component or element
            var code;
            if (el.component) {
                code = genComponent(el.component, el, state);
            } else {
                var data;
                if (!el.plain || (el.pre && state.maybeComponent(el))) {
                    data = genData$2(el, state);
                }

                var children = el.inlineTemplate ? null : genChildren(el, state, true);
                code = "_c('" + (el.tag) + "'" + (data ? ("," + data) : '') + (children ? ("," + children) : '') + ")";
            }
            // module transforms
            for (var i = 0; i < state.transforms.length; i++) {
                code = state.transforms[i](el, code);
            }
            return code
        }
    }

    // hoist static sub-trees out
    function genStatic (el, state) {
        el.staticProcessed = true;
        // Some elements (templates) need to behave differently inside of a v-pre
        // node.  All pre nodes are static roots, so we can use this as a location to
        // wrap a state change and reset it upon exiting the pre node.
        var originalPreState = state.pre;
        if (el.pre) {
            state.pre = el.pre;
        }
        state.staticRenderFns.push(("with(this){return " + (genElement(el, state)) + "}"));
        state.pre = originalPreState;
        return ("_m(" + (state.staticRenderFns.length - 1) + (el.staticInFor ? ',true' : '') + ")")
    }

    // v-once
    function genOnce (el, state) {
        el.onceProcessed = true;
        if (el.if && !el.ifProcessed) {
            return genIf(el, state)
        } else if (el.staticInFor) {
            var key = '';
            var parent = el.parent;
            while (parent) {
                if (parent.for) {
                    key = parent.key;
                    break
                }
                parent = parent.parent;
            }
            if (!key) {
                state.warn(
                    "v-once can only be used inside v-for that is keyed. ",
                    el.rawAttrsMap['v-once']
                );
                return genElement(el, state)
            }
            return ("_o(" + (genElement(el, state)) + "," + (state.onceId++) + "," + key + ")")
        } else {
            return genStatic(el, state)
        }
    }

    function genIf (
        el,
        state,
        altGen,
        altEmpty
    ) {
        el.ifProcessed = true; // avoid recursion
        return genIfConditions(el.ifConditions.slice(), state, altGen, altEmpty)
    }

    function genIfConditions (
        conditions,
        state,
        altGen,
        altEmpty
    ) {
        if (!conditions.length) {
            return altEmpty || '_e()'
        }

        var condition = conditions.shift();
        if (condition.exp) {
            return ("(" + (condition.exp) + ")?" + (genTernaryExp(condition.block)) + ":" + (genIfConditions(conditions, state, altGen, altEmpty)))
        } else {
            return ("" + (genTernaryExp(condition.block)))
        }

        // v-if with v-once should generate code like (a)?_m(0):_m(1)
        function genTernaryExp (el) {
            return altGen
                ? altGen(el, state)
                : el.once
                ? genOnce(el, state)
                : genElement(el, state)
        }
    }

    function genFor (
        el,
        state,
        altGen,
        altHelper
    ) {
        var exp = el.for;
        var alias = el.alias;
        var iterator1 = el.iterator1 ? ("," + (el.iterator1)) : '';
        var iterator2 = el.iterator2 ? ("," + (el.iterator2)) : '';

        if (state.maybeComponent(el) &&
            el.tag !== 'slot' &&
            el.tag !== 'template' &&
            !el.key
        ) {
            state.warn(
                "<" + (el.tag) + " v-for=\"" + alias + " in " + exp + "\">: component lists rendered with " +
                "v-for should have explicit keys. " +
                "See https://vuejs.org/guide/list.html#key for more info.",
                el.rawAttrsMap['v-for'],
                true /* tip */
            );
        }

        el.forProcessed = true; // avoid recursion
        return (altHelper || '_l') + "((" + exp + ")," +
            "function(" + alias + iterator1 + iterator2 + "){" +
            "return " + ((altGen || genElement)(el, state)) +
            '})'
    }

    function genData$2 (el, state) {
        var data = '{';

        // directives first.
        // directives may mutate the el's other properties before they are generated.
        var dirs = genDirectives(el, state);
        if (dirs) { data += dirs + ','; }

        // key
        if (el.key) {
            data += "key:" + (el.key) + ",";
        }
        // ref
        if (el.ref) {
            data += "ref:" + (el.ref) + ",";
        }
        if (el.refInFor) {
            data += "refInFor:true,";
        }
        // pre
        if (el.pre) {
            data += "pre:true,";
        }
        // record original tag name for components using "is" attribute
        if (el.component) {
            data += "tag:\"" + (el.tag) + "\",";
        }
        // module data generation functions
        for (var i = 0; i < state.dataGenFns.length; i++) {
            data += state.dataGenFns[i](el);
        }
        // attributes
        if (el.attrs) {
            data += "attrs:" + (genProps(el.attrs)) + ",";
        }
        // DOM props
        if (el.props) {
            data += "domProps:" + (genProps(el.props)) + ",";
        }
        // event handlers
        if (el.events) {
            data += (genHandlers(el.events, false)) + ",";
        }
        if (el.nativeEvents) {
            data += (genHandlers(el.nativeEvents, true)) + ",";
        }
        // slot target
        // only for non-scoped slots
        if (el.slotTarget && !el.slotScope) {
            data += "slot:" + (el.slotTarget) + ",";
        }
        // scoped slots
        if (el.scopedSlots) {
            data += (genScopedSlots(el, el.scopedSlots, state)) + ",";
        }
        // component v-model
        if (el.model) {
            data += "model:{value:" + (el.model.value) + ",callback:" + (el.model.callback) + ",expression:" + (el.model.expression) + "},";
        }
        // inline-template
        if (el.inlineTemplate) {
            var inlineTemplate = genInlineTemplate(el, state);
            if (inlineTemplate) {
                data += inlineTemplate + ",";
            }
        }
        data = data.replace(/,$/, '') + '}';
        // v-bind dynamic argument wrap
        // v-bind with dynamic arguments must be applied using the same v-bind object
        // merge helper so that class/style/mustUseProp attrs are handled correctly.
        if (el.dynamicAttrs) {
            data = "_b(" + data + ",\"" + (el.tag) + "\"," + (genProps(el.dynamicAttrs)) + ")";
        }
        // v-bind data wrap
        if (el.wrapData) {
            data = el.wrapData(data);
        }
        // v-on data wrap
        if (el.wrapListeners) {
            data = el.wrapListeners(data);
        }
        return data
    }

    function genDirectives (el, state) {
        var dirs = el.directives;
        if (!dirs) { return }
        var res = 'directives:[';
        var hasRuntime = false;
        var i, l, dir, needRuntime;
        for (i = 0, l = dirs.length; i < l; i++) {
            dir = dirs[i];
            needRuntime = true;
            var gen = state.directives[dir.name];
            if (gen) {
                // compile-time directive that manipulates AST.
                // returns true if it also needs a runtime counterpart.
                needRuntime = !!gen(el, dir, state.warn);
            }
            if (needRuntime) {
                hasRuntime = true;
                res += "{name:\"" + (dir.name) + "\",rawName:\"" + (dir.rawName) + "\"" + (dir.value ? (",value:(" + (dir.value) + "),expression:" + (JSON.stringify(dir.value))) : '') + (dir.arg ? (",arg:" + (dir.isDynamicArg ? dir.arg : ("\"" + (dir.arg) + "\""))) : '') + (dir.modifiers ? (",modifiers:" + (JSON.stringify(dir.modifiers))) : '') + "},";
            }
        }
        if (hasRuntime) {
            return res.slice(0, -1) + ']'
        }
    }

    function genInlineTemplate (el, state) {
        var ast = el.children[0];
        if (el.children.length !== 1 || ast.type !== 1) {
            state.warn(
                'Inline-template components must have exactly one child element.',
                { start: el.start }
            );
        }
        if (ast && ast.type === 1) {
            var inlineRenderFns = generate(ast, state.options);
            return ("inlineTemplate:{render:function(){" + (inlineRenderFns.render) + "},staticRenderFns:[" + (inlineRenderFns.staticRenderFns.map(function (code) { return ("function(){" + code + "}"); }).join(',')) + "]}")
        }
    }

    function genScopedSlots (
        el,
        slots,
        state
    ) {
        // by default scoped slots are considered "stable", this allows child
        // components with only scoped slots to skip forced updates from parent.
        // but in some cases we have to bail-out of this optimization
        // for example if the slot contains dynamic names, has v-if or v-for on them...
        var needsForceUpdate = el.for || Object.keys(slots).some(function (key) {
                var slot = slots[key];
                return (
                    slot.slotTargetDynamic ||
                    slot.if ||
                    slot.for ||
                    containsSlotChild(slot) // is passing down slot from parent which may be dynamic
                )
            });

        // #9534: if a component with scoped slots is inside a conditional branch,
        // it's possible for the same component to be reused but with different
        // compiled slot content. To avoid that, we generate a unique key based on
        // the generated code of all the slot contents.
        var needsKey = !!el.if;

        // OR when it is inside another scoped slot or v-for (the reactivity may be
        // disconnected due to the intermediate scope variable)
        // #9438, #9506
        // TODO: this can be further optimized by properly analyzing in-scope bindings
        // and skip force updating ones that do not actually use scope variables.
        if (!needsForceUpdate) {
            var parent = el.parent;
            while (parent) {
                if (
                    (parent.slotScope && parent.slotScope !== emptySlotScopeToken) ||
                    parent.for
                ) {
                    needsForceUpdate = true;
                    break
                }
                if (parent.if) {
                    needsKey = true;
                }
                parent = parent.parent;
            }
        }

        var generatedSlots = Object.keys(slots)
            .map(function (key) { return genScopedSlot(slots[key], state); })
            .join(',');

        return ("scopedSlots:_u([" + generatedSlots + "]" + (needsForceUpdate ? ",null,true" : "") + (!needsForceUpdate && needsKey ? (",null,false," + (hash(generatedSlots))) : "") + ")")
    }

    function hash(str) {
        var hash = 5381;
        var i = str.length;
        while(i) {
            hash = (hash * 33) ^ str.charCodeAt(--i);
        }
        return hash >>> 0
    }

    function containsSlotChild (el) {
        if (el.type === 1) {
            if (el.tag === 'slot') {
                return true
            }
            return el.children.some(containsSlotChild)
        }
        return false
    }

    function genScopedSlot (
        el,
        state
    ) {
        var isLegacySyntax = el.attrsMap['slot-scope'];
        if (el.if && !el.ifProcessed && !isLegacySyntax) {
            return genIf(el, state, genScopedSlot, "null")
        }
        if (el.for && !el.forProcessed) {
            return genFor(el, state, genScopedSlot)
        }
        var slotScope = el.slotScope === emptySlotScopeToken
            ? ""
            : String(el.slotScope);
        var fn = "function(" + slotScope + "){" +
            "return " + (el.tag === 'template'
                ? el.if && isLegacySyntax
                ? ("(" + (el.if) + ")?" + (genChildren(el, state) || 'undefined') + ":undefined")
                : genChildren(el, state) || 'undefined'
                : genElement(el, state)) + "}";
        // reverse proxy v-slot without scope on this.$slots
        var reverseProxy = slotScope ? "" : ",proxy:true";
        return ("{key:" + (el.slotTarget || "\"default\"") + ",fn:" + fn + reverseProxy + "}")
    }

    function genChildren (
        el,
        state,
        checkSkip,
        altGenElement,
        altGenNode
    ) {
        var children = el.children;
        if (children.length) {
            var el$1 = children[0];
            // optimize single v-for
            if (children.length === 1 &&
                el$1.for &&
                el$1.tag !== 'template' &&
                el$1.tag !== 'slot'
            ) {
                var normalizationType = checkSkip
                    ? state.maybeComponent(el$1) ? ",1" : ",0"
                    : "";
                return ("" + ((altGenElement || genElement)(el$1, state)) + normalizationType)
            }
            var normalizationType$1 = checkSkip
                ? getNormalizationType(children, state.maybeComponent)
                : 0;
            var gen = altGenNode || genNode;
            return ("[" + (children.map(function (c) { return gen(c, state); }).join(',')) + "]" + (normalizationType$1 ? ("," + normalizationType$1) : ''))
        }
    }

    // determine the normalization needed for the children array.
    // 0: no normalization needed
    // 1: simple normalization needed (possible 1-level deep nested array)
    // 2: full normalization needed
    function getNormalizationType (
        children,
        maybeComponent
    ) {
        var res = 0;
        for (var i = 0; i < children.length; i++) {
            var el = children[i];
            if (el.type !== 1) {
                continue
            }
            if (needsNormalization(el) ||
                (el.ifConditions && el.ifConditions.some(function (c) { return needsNormalization(c.block); }))) {
                res = 2;
                break
            }
            if (maybeComponent(el) ||
                (el.ifConditions && el.ifConditions.some(function (c) { return maybeComponent(c.block); }))) {
                res = 1;
            }
        }
        return res
    }

    function needsNormalization (el) {
        return el.for !== undefined || el.tag === 'template' || el.tag === 'slot'
    }

    function genNode (node, state) {
        if (node.type === 1) {
            return genElement(node, state)
        } else if (node.type === 3 && node.isComment) {
            return genComment(node)
        } else {
            return genText(node)
        }
    }

    function genText (text) {
        return ("_v(" + (text.type === 2
            ? text.expression // no need for () because already wrapped in _s()
            : transformSpecialNewlines(JSON.stringify(text.text))) + ")")
    }

    function genComment (comment) {
        return ("_e(" + (JSON.stringify(comment.text)) + ")")
    }

    function genSlot (el, state) {
        var slotName = el.slotName || '"default"';
        var children = genChildren(el, state);
        var res = "_t(" + slotName + (children ? ("," + children) : '');
        var attrs = el.attrs || el.dynamicAttrs
            ? genProps((el.attrs || []).concat(el.dynamicAttrs || []).map(function (attr) { return ({
            // slot props are camelized
            name: camelize(attr.name),
            value: attr.value,
            dynamic: attr.dynamic
        }); }))
            : null;
        var bind$$1 = el.attrsMap['v-bind'];
        if ((attrs || bind$$1) && !children) {
            res += ",null";
        }
        if (attrs) {
            res += "," + attrs;
        }
        if (bind$$1) {
            res += (attrs ? '' : ',null') + "," + bind$$1;
        }
        return res + ')'
    }

    // componentName is el.component, take it as argument to shun flow's pessimistic refinement
    function genComponent (
        componentName,
        el,
        state
    ) {
        var children = el.inlineTemplate ? null : genChildren(el, state, true);
        return ("_c(" + componentName + "," + (genData$2(el, state)) + (children ? ("," + children) : '') + ")")
    }

    function genProps (props) {
        var staticProps = "";
        var dynamicProps = "";
        for (var i = 0; i < props.length; i++) {
            var prop = props[i];
            var value = transformSpecialNewlines(prop.value);
            if (prop.dynamic) {
                dynamicProps += (prop.name) + "," + value + ",";
            } else {
                staticProps += "\"" + (prop.name) + "\":" + value + ",";
            }
        }
        staticProps = "{" + (staticProps.slice(0, -1)) + "}";
        if (dynamicProps) {
            return ("_d(" + staticProps + ",[" + (dynamicProps.slice(0, -1)) + "])")
        } else {
            return staticProps
        }
    }

    // #3895, #4268
    function transformSpecialNewlines (text) {
        return text
            .replace(/\u2028/g, '\\u2028')
            .replace(/\u2029/g, '\\u2029')
    }

    /*  */



    // these keywords should not appear inside expressions, but operators like
    // typeof, instanceof and in are allowed
    var prohibitedKeywordRE = new RegExp('\\b' + (
            'do,if,for,let,new,try,var,case,else,with,await,break,catch,class,const,' +
            'super,throw,while,yield,delete,export,import,return,switch,default,' +
            'extends,finally,continue,debugger,function,arguments'
        ).split(',').join('\\b|\\b') + '\\b');

    // these unary operators should not be used as property/method names
    var unaryOperatorsRE = new RegExp('\\b' + (
            'delete,typeof,void'
        ).split(',').join('\\s*\\([^\\)]*\\)|\\b') + '\\s*\\([^\\)]*\\)');

    // strip strings in expressions
    var stripStringRE = /'(?:[^'\\]|\\.)*'|"(?:[^"\\]|\\.)*"|`(?:[^`\\]|\\.)*\$\{|\}(?:[^`\\]|\\.)*`|`(?:[^`\\]|\\.)*`/g;

    // detect problematic expressions in a template
    function detectErrors (ast, warn) {
        if (ast) {
            checkNode(ast, warn);
        }
    }

    function checkNode (node, warn) {
        if (node.type === 1) {
            for (var name in node.attrsMap) {
                if (dirRE.test(name)) {
                    var value = node.attrsMap[name];
                    if (value) {
                        var range = node.rawAttrsMap[name];
                        if (name === 'v-for') {
                            checkFor(node, ("v-for=\"" + value + "\""), warn, range);
                        } else if (onRE.test(name)) {
                            checkEvent(value, (name + "=\"" + value + "\""), warn, range);
                        } else {
                            checkExpression(value, (name + "=\"" + value + "\""), warn, range);
                        }
                    }
                }
            }
            if (node.children) {
                for (var i = 0; i < node.children.length; i++) {
                    checkNode(node.children[i], warn);
                }
            }
        } else if (node.type === 2) {
            checkExpression(node.expression, node.text, warn, node);
        }
    }

    function checkEvent (exp, text, warn, range) {
        var stipped = exp.replace(stripStringRE, '');
        var keywordMatch = stipped.match(unaryOperatorsRE);
        if (keywordMatch && stipped.charAt(keywordMatch.index - 1) !== '$') {
            warn(
                "avoid using JavaScript unary operator as property name: " +
                "\"" + (keywordMatch[0]) + "\" in expression " + (text.trim()),
                range
            );
        }
        checkExpression(exp, text, warn, range);
    }

    function checkFor (node, text, warn, range) {
        checkExpression(node.for || '', text, warn, range);
        checkIdentifier(node.alias, 'v-for alias', text, warn, range);
        checkIdentifier(node.iterator1, 'v-for iterator', text, warn, range);
        checkIdentifier(node.iterator2, 'v-for iterator', text, warn, range);
    }

    function checkIdentifier (
        ident,
        type,
        text,
        warn,
        range
    ) {
        if (typeof ident === 'string') {
            try {
                new Function(("var " + ident + "=_"));
            } catch (e) {
                warn(("invalid " + type + " \"" + ident + "\" in expression: " + (text.trim())), range);
            }
        }
    }

    function checkExpression (exp, text, warn, range) {
        try {
            new Function(("return " + exp));
        } catch (e) {
            var keywordMatch = exp.replace(stripStringRE, '').match(prohibitedKeywordRE);
            if (keywordMatch) {
                warn(
                    "avoid using JavaScript keyword as property name: " +
                    "\"" + (keywordMatch[0]) + "\"\n  Raw expression: " + (text.trim()),
                    range
                );
            } else {
                warn(
                    "invalid expression: " + (e.message) + " in\n\n" +
                    "    " + exp + "\n\n" +
                    "  Raw expression: " + (text.trim()) + "\n",
                    range
                );
            }
        }
    }

    /*  */

    var range = 2;

    function generateCodeFrame (
        source,
        start,
        end
    ) {
        if ( start === void 0 ) start = 0;
        if ( end === void 0 ) end = source.length;

        var lines = source.split(/\r?\n/);
        var count = 0;
        var res = [];
        for (var i = 0; i < lines.length; i++) {
            count += lines[i].length + 1;
            if (count >= start) {
                for (var j = i - range; j <= i + range || end > count; j++) {
                    if (j < 0 || j >= lines.length) { continue }
                    res.push(("" + (j + 1) + (repeat$1(" ", 3 - String(j + 1).length)) + "|  " + (lines[j])));
                    var lineLength = lines[j].length;
                    if (j === i) {
                        // push underline
                        var pad = start - (count - lineLength) + 1;
                        var length = end > count ? lineLength - pad : end - start;
                        res.push("   |  " + repeat$1(" ", pad) + repeat$1("^", length));
                    } else if (j > i) {
                        if (end > count) {
                            var length$1 = Math.min(end - count, lineLength);
                            res.push("   |  " + repeat$1("^", length$1));
                        }
                        count += lineLength + 1;
                    }
                }
                break
            }
        }
        return res.join('\n')
    }

    function repeat$1 (str, n) {
        var result = '';
        if (n > 0) {
            while (true) { // eslint-disable-line
                if (n & 1) { result += str; }
                n >>>= 1;
                if (n <= 0) { break }
                str += str;
            }
        }
        return result
    }

    /*  */



    function createFunction (code, errors) {
        try {
            return new Function(code)
        } catch (err) {
            errors.push({ err: err, code: code });
            return noop
        }
    }

    function createCompileToFunctionFn (compile) {
        var cache = Object.create(null);

        return function compileToFunctions (
            template,
            options,
            vm
        ) {
            options = extend({}, options);
            var warn$$1 = options.warn || warn;
            delete options.warn;

            /* istanbul ignore if */
            {
                // detect possible CSP restriction
                try {
                    new Function('return 1');
                } catch (e) {
                    if (e.toString().match(/unsafe-eval|CSP/)) {
                        warn$$1(
                            'It seems you are using the standalone build of Vue.js in an ' +
                            'environment with Content Security Policy that prohibits unsafe-eval. ' +
                            'The template compiler cannot work in this environment. Consider ' +
                            'relaxing the policy to allow unsafe-eval or pre-compiling your ' +
                            'templates into render functions.'
                        );
                    }
                }
            }

            // check cache
            var key = options.delimiters
                ? String(options.delimiters) + template
                : template;
            if (cache[key]) {
                return cache[key]
            }

            // compile
            var compiled = compile(template, options);

            // check compilation errors/tips
            {
                if (compiled.errors && compiled.errors.length) {
                    if (options.outputSourceRange) {
                        compiled.errors.forEach(function (e) {
                            warn$$1(
                                "Error compiling template:\n\n" + (e.msg) + "\n\n" +
                                generateCodeFrame(template, e.start, e.end),
                                vm
                            );
                        });
                    } else {
                        warn$$1(
                            "Error compiling template:\n\n" + template + "\n\n" +
                            compiled.errors.map(function (e) { return ("- " + e); }).join('\n') + '\n',
                            vm
                        );
                    }
                }
                if (compiled.tips && compiled.tips.length) {
                    if (options.outputSourceRange) {
                        compiled.tips.forEach(function (e) { return tip(e.msg, vm); });
                    } else {
                        compiled.tips.forEach(function (msg) { return tip(msg, vm); });
                    }
                }
            }

            // turn code into functions
            var res = {};
            var fnGenErrors = [];
            res.render = createFunction(compiled.render, fnGenErrors);
            res.staticRenderFns = compiled.staticRenderFns.map(function (code) {
                return createFunction(code, fnGenErrors)
            });

            // check function generation errors.
            // this should only happen if there is a bug in the compiler itself.
            // mostly for codegen development use
            /* istanbul ignore if */
            {
                if ((!compiled.errors || !compiled.errors.length) && fnGenErrors.length) {
                    warn$$1(
                        "Failed to generate render function:\n\n" +
                        fnGenErrors.map(function (ref) {
                            var err = ref.err;
                            var code = ref.code;

                            return ((err.toString()) + " in\n\n" + code + "\n");
                        }).join('\n'),
                        vm
                    );
                }
            }

            return (cache[key] = res)
        }
    }

    /*  */

    function createCompilerCreator (baseCompile) {
        return function createCompiler (baseOptions) {
            function compile (
                template,
                options
            ) {
                var finalOptions = Object.create(baseOptions);
                var errors = [];
                var tips = [];

                var warn = function (msg, range, tip) {
                    (tip ? tips : errors).push(msg);
                };

                if (options) {
                    if (options.outputSourceRange) {
                        // $flow-disable-line
                        var leadingSpaceLength = template.match(/^\s*/)[0].length;

                        warn = function (msg, range, tip) {
                            var data = { msg: msg };
                            if (range) {
                                if (range.start != null) {
                                    data.start = range.start + leadingSpaceLength;
                                }
                                if (range.end != null) {
                                    data.end = range.end + leadingSpaceLength;
                                }
                            }
                            (tip ? tips : errors).push(data);
                        };
                    }
                    // merge custom modules
                    if (options.modules) {
                        finalOptions.modules =
                            (baseOptions.modules || []).concat(options.modules);
                    }
                    // merge custom directives
                    if (options.directives) {
                        finalOptions.directives = extend(
                            Object.create(baseOptions.directives || null),
                            options.directives
                        );
                    }
                    // copy other options
                    for (var key in options) {
                        if (key !== 'modules' && key !== 'directives') {
                            finalOptions[key] = options[key];
                        }
                    }
                }

                finalOptions.warn = warn;

                var compiled = baseCompile(template.trim(), finalOptions);
                {
                    detectErrors(compiled.ast, warn);
                }
                compiled.errors = errors;
                compiled.tips = tips;
                return compiled
            }

            return {
                compile: compile,
                compileToFunctions: createCompileToFunctionFn(compile)
            }
        }
    }

    /*  */

    // `createCompilerCreator` allows creating compilers that use alternative
    // parser/optimizer/codegen, e.g the SSR optimizing compiler.
    // Here we just export a default compiler using the default parts.
    var createCompiler = createCompilerCreator(function baseCompile (
        template,
        options
    ) {
        var ast = parse(template.trim(), options);
        if (options.optimize !== false) {
            optimize(ast, options);
        }
        var code = generate(ast, options);
        return {
            ast: ast,
            render: code.render,
            staticRenderFns: code.staticRenderFns
        }
    });

    /*  */

    var ref$1 = createCompiler(baseOptions);
    var compile = ref$1.compile;
    var compileToFunctions = ref$1.compileToFunctions;

    /*  */

    // check whether current browser encodes a char inside attribute values
    var div;
    function getShouldDecode (href) {
        div = div || document.createElement('div');
        div.innerHTML = href ? "<a href=\"\n\"/>" : "<div a=\"\n\"/>";
        return div.innerHTML.indexOf('&#10;') > 0
    }

    // #3663: IE encodes newlines inside attribute values while other browsers don't
    var shouldDecodeNewlines = inBrowser ? getShouldDecode(false) : false;
    // #6828: chrome encodes content in a[href]
    var shouldDecodeNewlinesForHref = inBrowser ? getShouldDecode(true) : false;

    /*  */

    var idToTemplate = cached(function (id) {
        var el = query(id);
        return el && el.innerHTML
    });

    var mount = Vue.prototype.$mount;
    Vue.prototype.$mount = function (
        el,
        hydrating
    ) {
        el = el && query(el);

        /* istanbul ignore if */
        if (el === document.body || el === document.documentElement) {
            warn(
                "Do not mount Vue to <html> or <body> - mount to normal elements instead."
            );
            return this
        }

        var options = this.$options;
        // resolve template/el and convert to render function
        if (!options.render) {
            var template = options.template;
            if (template) {
                if (typeof template === 'string') {
                    if (template.charAt(0) === '#') {
                        template = idToTemplate(template);
                        /* istanbul ignore if */
                        if (!template) {
                            warn(
                                ("Template element not found or is empty: " + (options.template)),
                                this
                            );
                        }
                    }
                } else if (template.nodeType) {
                    template = template.innerHTML;
                } else {
                    {
                        warn('invalid template option:' + template, this);
                    }
                    return this
                }
            } else if (el) {
                template = getOuterHTML(el);
            }
            if (template) {
                /* istanbul ignore if */
                if (config.performance && mark) {
                    mark('compile');
                }

                var ref = compileToFunctions(template, {
                    outputSourceRange: "development" !== 'production',
                    shouldDecodeNewlines: shouldDecodeNewlines,
                    shouldDecodeNewlinesForHref: shouldDecodeNewlinesForHref,
                    delimiters: options.delimiters,
                    comments: options.comments
                }, this);
                var render = ref.render;
                var staticRenderFns = ref.staticRenderFns;
                options.render = render;
                options.staticRenderFns = staticRenderFns;

                /* istanbul ignore if */
                if (config.performance && mark) {
                    mark('compile end');
                    measure(("vue " + (this._name) + " compile"), 'compile', 'compile end');
                }
            }
        }
        return mount.call(this, el, hydrating)
    };

    /**
     * Get outerHTML of elements, taking care
     * of SVG elements in IE as well.
     */
    function getOuterHTML (el) {
        if (el.outerHTML) {
            return el.outerHTML
        } else {
            var container = document.createElement('div');
            container.appendChild(el.cloneNode(true));
            return container.innerHTML
        }
    }

    Vue.compile = compileToFunctions;

    return Vue;

}));